Steps to reproduce the issue

On a current 5.2-dev branch or nightly build (works also with 5.3-dev and 5.4-dev), install blog sample data.

Expected result

Works.

Actual result

Fails with message "There is an error in a sample data plugin. Response is invalid."

In PHP error log multiple times:

PHP Notice:  Undefined property via __get(): mariadb in /joomlaroot/libraries/vendor/joomla/database/src/Query/MysqlQueryBuilder.php on line 221 in /joomlaroot/libraries/vendor/joomla/database/src/DatabaseQuery.php on line 485, referer: https://www.joomla-52-dev.vmubu02.vmnet2.local/administrator/index.php
PHP Stack trace:, referer: https://www.joomla-52-dev.vmubu02.vmnet2.local/administrator/index.php
PHP   1. {main}() /joomlaroot/administrator/index.php:0, referer: https://www.joomla-52-dev.vmubu02.vmnet2.local/administrator/index.php
PHP   2. require_once() /joomlaroot/administrator/index.php:32, referer: https://www.joomla-52-dev.vmubu02.vmnet2.local/administrator/index.php
PHP   3. Joomla\\CMS\\Application\\CMSApplication->execute() /joomlaroot/administrator/includes/app.php:58, referer: https://www.joomla-52-dev.vmubu02.vmnet2.local/administrator/index.php
PHP   4. Joomla\\CMS\\Application\\AdministratorApplication->doExecute() /joomlaroot/libraries/src/Application/CMSApplication.php:306, referer: https://www.joomla-52-dev.vmubu02.vmnet2.local/administrator/index.php
PHP   5. Joomla\\CMS\\Application\\AdministratorApplication->dispatch($component = *uninitialized*) /joomlaroot/libraries/src/Application/AdministratorApplication.php:205, referer: https://www.joomla-52-dev.vmubu02.vmnet2.local/administrator/index.php
PHP   6. Joomla\\CMS\\Component\\ComponentHelper::renderComponent($option = 'com_ajax', $params = *uninitialized*) /joomlaroot/libraries/src/Application/AdministratorApplication.php:150, referer: https://www.joomla-52-dev.vmubu02.vmnet2.local/administrator/index.php
PHP   7. Joomla\\CMS\\Dispatcher\\LegacyComponentDispatcher->dispatch() /joomlaroot/libraries/src/Component/ComponentHelper.php:361, referer: https://www.joomla-52-dev.vmubu02.vmnet2.local/administrator/index.php
PHP   8. Joomla\\CMS\\Dispatcher\\LegacyComponentDispatcher::Joomla\\CMS\\Dispatcher\\{closure:/joomlaroot/libraries/src/Dispatcher/LegacyComponentDispatcher.php:70-72}($path = '/joomlaroot/administrator/components/com_ajax/ajax.php') /joomlaroot/libraries/src/Dispatcher/LegacyComponentDispatcher.php:73, referer: https://www.joomla-52-dev.vmubu02.vmnet2.local/administrator/index.php
PHP   9. require_once() /joomlaroot/libraries/src/Dispatcher/LegacyComponentDispatcher.php:71, referer: https://www.joomla-52-dev.vmubu02.vmnet2.local/administrator/index.php
PHP  10. require_once() /joomlaroot/administrator/components/com_ajax/ajax.php:13, referer: https://www.joomla-52-dev.vmubu02.vmnet2.local/administrator/index.php
PHP  11. Joomla\\Event\\Dispatcher->dispatch($name = 'onAjaxSampledataApplyStep1', $event = class Joomla\\CMS\\Event\\Plugin\\AjaxEvent { protected $name = 'onAjaxSampledataApplyStep1'; protected $arguments = ['subject' => class Joomla\\CMS\\Application\\AdministratorApplication { ... }]; protected $stopped = FALSE; private ${Joomla\\CMS\\Event\\AbstractImmutableEvent}constructed = TRUE }) /joomlaroot/components/com_ajax/ajax.php:136, referer: https://www.joomla-52-dev.vmubu02.vmnet2.local/administrator/index.php
PHP  12. Joomla\\CMS\\Plugin\\CMSPlugin->Joomla\\CMS\\Plugin\\{closure:/joomlaroot/libraries/src/Plugin/CMSPlugin.php:273-303}($event = class Joomla\\CMS\\Event\\Plugin\\AjaxEvent { protected $name = 'onAjaxSampledataApplyStep1'; protected $arguments = ['subject' => class Joomla\\CMS\\Application\\AdministratorApplication { ... }]; protected $stopped = FALSE; private ${Joomla\\CMS\\Event\\AbstractImmutableEvent}constructed = TRUE }) /joomlaroot/libraries/vendor/joomla/event/src/Dispatcher.php:454, referer: https://www.joomla-52-dev.vmubu02.vmnet2.local/administrator/index.php
PHP  13. Joomla\\Plugin\\SampleData\\Blog\\Extension\\Blog->onAjaxSampledataApplyStep1(class Joomla\\CMS\\Application\\AdministratorApplication { protected $config = class Joomla\\Registry\\Registry { protected $data = class stdClass { ... }; protected $initialized = TRUE; protected $separator = '.' }; protected ?Psr\\Log\\LoggerInterface $logger = class Joomla\\CMS\\Log\\DelegatingPsrLogger { protected $logger = class Joomla\\CMS\\Log\\Log { ... }; protected $priorityMap = [...] }; private ${Joomla\\Application\\AbstractApplication}dispatcher = class Joomla\\Event\\Dispatcher { protected $events = [...]; protected $listeners = [...] }; protected $input = class Joomla\\CMS\\Input\\Input { protected $options = [...]; protected $filter = class Joomla\\Filter\\InputFilter { ... }; protected $data = [...]; protected $inputs = [...] }; public $charSet = 'utf-8'; public $mimeType = 'text/html'; public $httpVersion = '1.1'; public $modifiedDate = NULL; public $client = class Joomla\\Application\\Web\\WebClient { protected $platform = NULL; protected $mobile = FALSE; protected $engine = NULL; protected $browser = NULL; protected $browserVersion = NULL; protected $languages = [...]; protected $encodings = [...]; protected $userAgent = 'Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:137.0) Gecko/20100101 Firefox/137.0'; protected $acceptEncoding = 'gzip, deflate, br, zstd'; protected $acceptLanguage = 'de-DE,de;q=0.8,en-US;q=0.5,en;q=0.3'; protected $robot = FALSE; protected $detection = [...]; protected $headers = NULL }; protected $response = class Laminas\\Diactoros\\Response { private array $phrases = [...]; private string $reasonPhrase = 'OK'; private int $statusCode = 200; protected $headers = [...]; protected $headerNames = [...]; private $protocol = '1.1'; private $stream = class Laminas\\Diactoros\\Stream { ... } }; private ${Joomla\\Application\\AbstractWebApplication}cacheable = FALSE; private ${Joomla\\Application\\AbstractWebApplication}responseMap = [100 => 'HTTP/{version} 100 Continue', 101 => 'HTTP/{version} 101 Switching Protocols', 102 => 'HTTP/{version} 102 Processing', 200 => 'HTTP/{version} 200 OK', 201 => 'HTTP/{version} 201 Created', 202 => 'HTTP/{version} 202 Accepted', 203 => 'HTTP/{version} 203 Non-Authoritative Information', 204 => 'HTTP/{version} 204 No Content', 205 => 'HTTP/{version} 205 Reset Content', 206 => 'HTTP/{version} 206 Partial Content', 207 => 'HTTP/{version} 207 Multi-Status', 208 => 'HTTP/{version} 208 Already Reported', 226 => 'HTTP/{version} 226 IM Used', 300 => 'HTTP/{version} 300 Multiple Choices', 301 => 'HTTP/{version} 301 Moved Permanently', 302 => 'HTTP/{version} 302 Found', 303 => 'HTTP/{version} 303 See other', 304 => 'HTTP/{version} 304 Not Modified', 305 => 'HTTP/{version} 305 Use Proxy', 306 => 'HTTP/{version} 306 (Unused)', 307 => 'HTTP/{version} 307 Temporary Redirect', 308 => 'HTTP/{version} 308 Permanent Redirect', 400 => 'HTTP/{version} 400 Bad Request', 401 => 'HTTP/{version} 401 Unauthorized', 402 => 'HTTP/{version} 402 Payment Required', 403 => 'HTTP/{version} 403 Forbidden', 404 => 'HTTP/{version} 404 Not Found', 405 => 'HTTP/{version} 405 Method Not Allowed', 406 => 'HTTP/{version} 406 Not Acceptable', 407 => 'HTTP/{version} 407 Proxy Authentication Required', 408 => 'HTTP/{version} 408 Request Timeout', 409 => 'HTTP/{version} 409 Conflict', 410 => 'HTTP/{version} 410 Gone', 411 => 'HTTP/{version} 411 Length Required', 412 => 'HTTP/{version} 412 Precondition Failed', 413 => 'HTTP/{version} 413 Payload Too Large', 414 => 'HTTP/{version} 414 URI Too Long', 415 => 'HTTP/{version} 415 Unsupported Media Type', 416 => 'HTTP/{version} 416 Range Not Satisfiable', 417 => 'HTTP/{version} 417 Expectation Failed', 418 => 'HTTP/{version} 418 I\\'m a teapot', 421 => 'HTTP/{version} 421 Misdirected Request', 422 => 'HTTP/{version} 422 Unprocessable Entity', 423 => 'HTTP/{version} 423 Locked', 424 => 'HTTP/{version} 424 Failed Dependency', 426 => 'HTTP/{version} 426 Upgrade Required', 428 => 'HTTP/{version} 428 Precondition Required', 429 => 'HTTP/{version} 429 Too Many Requests', 431 => 'HTTP/{version} 431 Request Header Fields Too Large', 451 => 'HTTP/{version} 451 Unavailable For Legal Reasons', 500 => 'HTTP/{version} 500 Internal Server Error', 501 => 'HTTP/{version} 501 Not Implemented', 502 => 'HTTP/{version} 502 Bad Gateway', 503 => 'HTTP/{version} 503 Service Unavailable', 504 => 'HTTP/{version} 504 Gateway Timeout', 505 => 'HTTP/{version} 505 HTTP Version Not Supported', 506 => 'HTTP/{version} 506 Variant Also Negotiates', 507 => 'HTTP/{version} 507 Insufficient Storage', 508 => 'HTTP/{version} 508 Loop Detected', 510 => 'HTTP/{version} 510 Not Extended', 511 => 'HTTP/{version} 511 Network Authentication Required']; public $JComponentTitle = NULL; public $item_associations = NULL; protected $document = class Joomla\\CMS\\Document\\JsonDocument { public $title = 'Joomla 5.2-dev at vmubu02 - Administration'; public $description = NULL; public $link = ''; public $base = ''; public $language = 'en-gb'; public $direction = 'ltr'; public $_generator = 'Joomla! - Open Source Content Management'; public $_mdate = ''; public $_tab = '\\t'; public $_lineEnd = '\\n'; public $_charset = 'utf-8'; public $_mime = 'application/json'; public $_namespace = ''; public $_profile = ''; public $_scripts = [...]; public $_script = [...]; protected $scriptOptions = [...]; public $_styleSheets = [...]; public $_style = [...]; public $_metaTags = [...]; public $_engine = NULL; public $_type = 'json'; protected $mediaVersion = '92d725'; protected $factory = class Joomla\\CMS\\Document\\Factory { ... }; protected $preloadManager = class Joomla\\CMS\\Document\\PreloadManager { ... }; protected $preloadTypes = [...]; protected $webAssetManager = class Joomla\\CMS\\WebAsset\\WebAssetManager { ... }; protected $_name = 'joomla' }; protected $language = class Joomla\\CMS\\Language\\Language { protected $debug = FALSE; protected $default = 'en-GB'; protected $orphans = [...]; protected $metadata = [...]; protected $locale = NULL; protected $lang = 'en-GB'; protected $paths = [...]; protected $errorfiles = [...]; protected $used = [...]; protected $counter = 33; protected $override = [...]; protected $localise = NULL; protected $helper = NULL; protected $basePath = NULL; protected $catalogue = NULL; protected $parserRegistry = NULL; protected $strings = [...]; protected $transliterator = NULL; protected $pluralSuffixesCallback = [...]; protected $ignoredSearchWordsCallback = NULL; protected $lowerLimitSearchWordCallback = NULL; protected $upperLimitSearchWordCallback = NULL; protected $searchDisplayedCharactersNumberCallback = NULL }; protected $identity = class Joomla\\CMS\\User\\User { protected $isRoot = TRUE; public $id = 449; public $name = 'Richard'; public $username = 'rfadmin'; public $email = 'admin@richard-fath.de'; public $password = '$2y$10$m2q445OmCGAixhOgju.UaeUcOt/9.KR3kGTXQtBy.U3Pu/0EJjRgu'; public $password_clear = ''; public $block = 0; public $sendEmail = 1; public $registerDate = '2025-04-06 12:25:24'; public $lastvisitDate = '2025-04-06 12:34:09'; public $activation = '0'; public $params = ''; public $groups = [...]; public $guest = 0; public $lastResetTime = NULL; public $resetCount = 0; public $requireReset = 0; public $typeAlias = NULL; public $otpKey = ''; public $otep = ''; public $authProvider = ''; protected $_params = class Joomla\\Registry\\Registry { ... }; protected $_authGroups = [...]; protected $_authLevels = [...]; protected $_authActions = NULL; protected $_errorMsg = NULL; protected $_errors = [...] }; private ${Joomla\\CMS\\Application\\WebApplication}userFactory = class Joomla\\CMS\\User\\UserFactory { private $db = class Joomla\\Database\\Mysqli\\MysqliDriver { ... } }; protected $docOptions = []; public $scope = 'com_ajax'; protected $clientId = 1; protected $messageQueue = []; protected $name = 'administrator'; protected $profiler = class Joomla\\CMS\\Profiler\\Profiler { protected $start = 1743942857.7924; protected $prefix = 'Application'; protected $buffer = [...]; protected $marks = [...]; p
PHP  14. Joomla\\Component\\Content\\Administrator\\Model\\ArticleModel->save($data = ['catid' => 9, 'title' => 'About', 'introtext' => '<p>This tells you a bit about this blog and the person who writes it.</p><p>When you are logged in you will be able to edit this page by selecting the edit icon.</p>', 'fulltext' => '', 'id' => 0, 'ordering' => 0, 'created_user_id' => 449, 'created_by_alias' => 'Joomla', 'alias' => 'about', 'language' => '*', 'associations' => [], 'metakey' => '', 'metadesc' => '', 'featured' => 0, 'state' => 1, 'images' => '', 'access' => 1]) /joomlaroot/plugins/sampledata/blog/src/Extension/Blog.php:716, referer: https://www.joomla-52-dev.vmubu02.vmnet2.local/administrator/index.php
PHP  15. Joomla\\CMS\\MVC\\Model\\AdminModel->save($data = ['catid' => 9, 'title' => 'About', 'introtext' => '<p>This tells you a bit about this blog and the person who writes it.</p><p>When you are logged in you will be able to edit this page by selecting the edit icon.</p>', 'fulltext' => '', 'id' => 0, 'ordering' => 0, 'created_user_id' => 449, 'created_by_alias' => 'Joomla', 'alias' => 'about', 'language' => '*', 'associations' => [], 'metakey' => '', 'metadesc' => '', 'featured' => 0, 'state' => 1, 'images' => '', 'access' => 1]) /joomlaroot/administrator/components/com_content/src/Model/ArticleModel.php:780, referer: https://www.joomla-52-dev.vmubu02.vmnet2.local/administrator/index.php
PHP  16. Joomla\\Component\\Content\\Administrator\\Model\\ArticleModel->prepareTable($table = class Joomla\\Component\\Content\\Administrator\\Table\\ArticleTable { protected $_tbl = '#__content'; protected $_tbl_key = 'id'; protected $_tbl_keys = [0 => 'id']; protected $_db = class Joomla\\Database\\Mysqli\\MysqliDriver { private ${Joomla\\Database\\DatabaseDriver}database = 'joomladb1'; public $name = 'mysqli'; public $serverType = 'mysql'; protected $connection = class mysqli { ... }; protected $count = 976; protected $cursor = NULL; protected $executed = FALSE; protected $limit = 0; protected $nameQuote = '`'; protected $nullDate = '0000-00-00 00:00:00'; protected $offset = 0; protected $options = [...]; protected $sql = class Joomla\\Database\\Mysqli\\MysqliQuery { ... }; protected $statement = class Joomla\\Database\\Mysqli\\MysqliStatement { ... }; protected $tablePrefix = 'j3ux0_'; protected $utf = TRUE; protected $errorNum = 0; protected $errorMsg = NULL; protected $transactionDepth = 0; protected $factory = class Joomla\\Database\\DatabaseFactory { ... }; protected $monitor = class Joomla\\Database\\Monitor\\DebugMonitor { ... }; private ${Joomla\\Database\\DatabaseDriver}dispatcher = class Joomla\\Event\\Dispatcher { ... }; protected $utf8mb4 = TRUE; protected $mariadb = FALSE }; protected $_trackAssets = TRUE; protected $_rules = NULL; protected $_locked = FALSE; protected $_autoincrement = TRUE; protected $_columnAlias = ['published' => 'state']; protected $_jsonEncode = []; protected $_supportNullValue = TRUE; public $typeAlias = 'com_content.article'; private ${Joomla\\CMS\\Table\\Table}dispatcher = class Joomla\\Event\\Dispatcher { protected $events = [...]; protected $listeners = [...] }; protected $_errors = []; public $tagsHelper = class Joomla\\CMS\\Helper\\TagsHelper { protected $tagsChanged = FALSE; protected $replaceTags = FALSE; public $typeAlias = 'com_content.article'; public $itemTags = NULL; public $tags = NULL; public $newTags = NULL; public $oldTags = NULL }; private ${Joomla\\CMS\\Table\\Content}currentUser = class Joomla\\CMS\\User\\User { protected $isRoot = TRUE; public $id = 449; public $name = 'Richard'; public $username = 'rfadmin'; public $email = 'admin@richard-fath.de'; public $password = '$2y$10$m2q445OmCGAixhOgju.UaeUcOt/9.KR3kGTXQtBy.U3Pu/0EJjRgu'; public $password_clear = ''; public $block = 0; public $sendEmail = 1; public $registerDate = '2025-04-06 12:25:24'; public $lastvisitDate = '2025-04-06 12:34:09'; public $activation = '0'; public $params = ''; public $groups = [...]; public $guest = 0; public $lastResetTime = NULL; public $resetCount = 0; public $requireReset = 0; public $typeAlias = NULL; public $otpKey = ''; public $otep = ''; public $authProvider = ''; protected $_params = class Joomla\\Registry\\Registry { ... }; protected $_authGroups = [...]; protected $_authLevels = [...]; protected $_authActions = NULL; protected $_errorMsg = NULL; protected $_errors = [...] }; public $id = 0; public $asset_id = NULL; public $title = 'About'; public $alias = 'about'; public $introtext = '<p>This tells you a bit about this blog and the person who writes it.</p><p>When you are logged in you will be able to edit this page by selecting the edit icon.</p>'; public $fulltext = ''; public $state = 1; public $catid = 9; public $created = NULL; public $created_by = NULL; public $created_by_alias = 'Joomla'; public $modified = NULL; public $modified_by = NULL; public $checked_out = NULL; public $checked_out_time = NULL; public $publish_up = '2025-04-06 12:34:17'; public $publish_down = NULL; public $images = ''; public $urls = NULL; public $attribs = NULL; public $version = 1; public $ordering = 0; public $metakey = ''; public $metadesc = ''; public $access = 1; public $hits = NULL; public $metadata = NULL; public $featured = 0; public $language = '*'; public $note = NULL }) /joomlaroot/libraries/src/MVC/Model/AdminModel.php:1275, referer: https://www.joomla-52-dev.vmubu02.vmnet2.local/administrator/index.php
PHP  17. Joomla\\CMS\\Table\\Table->reorder($where = 'catid = 9 AND state >= 0') /joomlaroot/administrator/components/com_content/src/Model/ArticleModel.php:354, referer: https://www.joomla-52-dev.vmubu02.vmnet2.local/administrator/index.php
PHP  18. Joomla\\Database\\Mysqli\\MysqliQuery->selectRowNumber($orderBy = '`ordering`', $orderColumnAlias = 'new_ordering') /joomlaroot/libraries/src/Table/Table.php:1487, referer: https://www.joomla-52-dev.vmubu02.vmnet2.local/administrator/index.php
PHP  19. Joomla\\Database\\DatabaseQuery->__get($name = 'mariadb') /joomlaroot/libraries/vendor/joomla/database/src/Query/MysqlQueryBuilder.php:221, referer: https://www.joomla-52-dev.vmubu02.vmnet2.local/administrator/index.php
PHP  20. trigger_error($message = 'Undefined property via __get(): mariadb in /joomlaroot/libraries/vendor/joomla/database/src/Query/MysqlQueryBuilder.php on line 221', $error_level = 1024) /joomlaroot/libraries/vendor/joomla/database/src/DatabaseQuery.php:485, referer: https://www.joomla-52-dev.vmubu02.vmnet2.local/administrator/index.php

and

PHP Notice:  Undefined property via __get(): mariadb in /joomlaroot/libraries/vendor/joomla/database/src/Query/MysqlQueryBuilder.php on line 221 in /joomlaroot/libraries/vendor/joomla/database/src/DatabaseQuery.php on line 485, referer: https://www.joomla-52-dev.vmubu02.vmnet2.local/administrator/index.php
PHP Stack trace:, referer: https://www.joomla-52-dev.vmubu02.vmnet2.local/administrator/index.php
PHP   1. {main}() /joomlaroot/administrator/index.php:0, referer: https://www.joomla-52-dev.vmubu02.vmnet2.local/administrator/index.php
PHP   2. require_once() /joomlaroot/administrator/index.php:32, referer: https://www.joomla-52-dev.vmubu02.vmnet2.local/administrator/index.php
PHP   3. Joomla\\CMS\\Application\\CMSApplication->execute() /joomlaroot/administrator/includes/app.php:58, referer: https://www.joomla-52-dev.vmubu02.vmnet2.local/administrator/index.php
PHP   4. Joomla\\CMS\\Application\\AdministratorApplication->doExecute() /joomlaroot/libraries/src/Application/CMSApplication.php:306, referer: https://www.joomla-52-dev.vmubu02.vmnet2.local/administrator/index.php
PHP   5. Joomla\\CMS\\Application\\AdministratorApplication->dispatch($component = *uninitialized*) /joomlaroot/libraries/src/Application/AdministratorApplication.php:205, referer: https://www.joomla-52-dev.vmubu02.vmnet2.local/administrator/index.php
PHP   6. Joomla\\CMS\\Component\\ComponentHelper::renderComponent($option = 'com_ajax', $params = *uninitialized*) /joomlaroot/libraries/src/Application/AdministratorApplication.php:150, referer: https://www.joomla-52-dev.vmubu02.vmnet2.local/administrator/index.php
PHP   7. Joomla\\CMS\\Dispatcher\\LegacyComponentDispatcher->dispatch() /joomlaroot/libraries/src/Component/ComponentHelper.php:361, referer: https://www.joomla-52-dev.vmubu02.vmnet2.local/administrator/index.php
PHP   8. Joomla\\CMS\\Dispatcher\\LegacyComponentDispatcher::Joomla\\CMS\\Dispatcher\\{closure:/joomlaroot/libraries/src/Dispatcher/LegacyComponentDispatcher.php:70-72}($path = '/joomlaroot/administrator/components/com_ajax/ajax.php') /joomlaroot/libraries/src/Dispatcher/LegacyComponentDispatcher.php:73, referer: https://www.joomla-52-dev.vmubu02.vmnet2.local/administrator/index.php
PHP   9. require_once() /joomlaroot/libraries/src/Dispatcher/LegacyComponentDispatcher.php:71, referer: https://www.joomla-52-dev.vmubu02.vmnet2.local/administrator/index.php
PHP  10. require_once() /joomlaroot/administrator/components/com_ajax/ajax.php:13, referer: https://www.joomla-52-dev.vmubu02.vmnet2.local/administrator/index.php
PHP  11. Joomla\\Event\\Dispatcher->dispatch($name = 'onAjaxSampledataApplyStep1', $event = class Joomla\\CMS\\Event\\Plugin\\AjaxEvent { protected $name = 'onAjaxSampledataApplyStep1'; protected $arguments = ['subject' => class Joomla\\CMS\\Application\\AdministratorApplication { ... }]; protected $stopped = FALSE; private ${Joomla\\CMS\\Event\\AbstractImmutableEvent}constructed = TRUE }) /joomlaroot/components/com_ajax/ajax.php:136, referer: https://www.joomla-52-dev.vmubu02.vmnet2.local/administrator/index.php
PHP  12. Joomla\\CMS\\Plugin\\CMSPlugin->Joomla\\CMS\\Plugin\\{closure:/joomlaroot/libraries/src/Plugin/CMSPlugin.php:273-303}($event = class Joomla\\CMS\\Event\\Plugin\\AjaxEvent { protected $name = 'onAjaxSampledataApplyStep1'; protected $arguments = ['subject' => class Joomla\\CMS\\Application\\AdministratorApplication { ... }]; protected $stopped = FALSE; private ${Joomla\\CMS\\Event\\AbstractImmutableEvent}constructed = TRUE }) /joomlaroot/libraries/vendor/joomla/event/src/Dispatcher.php:454, referer: https://www.joomla-52-dev.vmubu02.vmnet2.local/administrator/index.php
PHP  13. Joomla\\Plugin\\SampleData\\Blog\\Extension\\Blog->onAjaxSampledataApplyStep1(class Joomla\\CMS\\Application\\AdministratorApplication { protected $config = class Joomla\\Registry\\Registry { protected $data = class stdClass { ... }; protected $initialized = TRUE; protected $separator = '.' }; protected ?Psr\\Log\\LoggerInterface $logger = class Joomla\\CMS\\Log\\DelegatingPsrLogger { protected $logger = class Joomla\\CMS\\Log\\Log { ... }; protected $priorityMap = [...] }; private ${Joomla\\Application\\AbstractApplication}dispatcher = class Joomla\\Event\\Dispatcher { protected $events = [...]; protected $listeners = [...] }; protected $input = class Joomla\\CMS\\Input\\Input { protected $options = [...]; protected $filter = class Joomla\\Filter\\InputFilter { ... }; protected $data = [...]; protected $inputs = [...] }; public $charSet = 'utf-8'; public $mimeType = 'text/html'; public $httpVersion = '1.1'; public $modifiedDate = NULL; public $client = class Joomla\\Application\\Web\\WebClient { protected $platform = NULL; protected $mobile = FALSE; protected $engine = NULL; protected $browser = NULL; protected $browserVersion = NULL; protected $languages = [...]; protected $encodings = [...]; protected $userAgent = 'Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:137.0) Gecko/20100101 Firefox/137.0'; protected $acceptEncoding = 'gzip, deflate, br, zstd'; protected $acceptLanguage = 'de-DE,de;q=0.8,en-US;q=0.5,en;q=0.3'; protected $robot = FALSE; protected $detection = [...]; protected $headers = NULL }; protected $response = class Laminas\\Diactoros\\Response { private array $phrases = [...]; private string $reasonPhrase = 'OK'; private int $statusCode = 200; protected $headers = [...]; protected $headerNames = [...]; private $protocol = '1.1'; private $stream = class Laminas\\Diactoros\\Stream { ... } }; private ${Joomla\\Application\\AbstractWebApplication}cacheable = FALSE; private ${Joomla\\Application\\AbstractWebApplication}responseMap = [100 => 'HTTP/{version} 100 Continue', 101 => 'HTTP/{version} 101 Switching Protocols', 102 => 'HTTP/{version} 102 Processing', 200 => 'HTTP/{version} 200 OK', 201 => 'HTTP/{version} 201 Created', 202 => 'HTTP/{version} 202 Accepted', 203 => 'HTTP/{version} 203 Non-Authoritative Information', 204 => 'HTTP/{version} 204 No Content', 205 => 'HTTP/{version} 205 Reset Content', 206 => 'HTTP/{version} 206 Partial Content', 207 => 'HTTP/{version} 207 Multi-Status', 208 => 'HTTP/{version} 208 Already Reported', 226 => 'HTTP/{version} 226 IM Used', 300 => 'HTTP/{version} 300 Multiple Choices', 301 => 'HTTP/{version} 301 Moved Permanently', 302 => 'HTTP/{version} 302 Found', 303 => 'HTTP/{version} 303 See other', 304 => 'HTTP/{version} 304 Not Modified', 305 => 'HTTP/{version} 305 Use Proxy', 306 => 'HTTP/{version} 306 (Unused)', 307 => 'HTTP/{version} 307 Temporary Redirect', 308 => 'HTTP/{version} 308 Permanent Redirect', 400 => 'HTTP/{version} 400 Bad Request', 401 => 'HTTP/{version} 401 Unauthorized', 402 => 'HTTP/{version} 402 Payment Required', 403 => 'HTTP/{version} 403 Forbidden', 404 => 'HTTP/{version} 404 Not Found', 405 => 'HTTP/{version} 405 Method Not Allowed', 406 => 'HTTP/{version} 406 Not Acceptable', 407 => 'HTTP/{version} 407 Proxy Authentication Required', 408 => 'HTTP/{version} 408 Request Timeout', 409 => 'HTTP/{version} 409 Conflict', 410 => 'HTTP/{version} 410 Gone', 411 => 'HTTP/{version} 411 Length Required', 412 => 'HTTP/{version} 412 Precondition Failed', 413 => 'HTTP/{version} 413 Payload Too Large', 414 => 'HTTP/{version} 414 URI Too Long', 415 => 'HTTP/{version} 415 Unsupported Media Type', 416 => 'HTTP/{version} 416 Range Not Satisfiable', 417 => 'HTTP/{version} 417 Expectation Failed', 418 => 'HTTP/{version} 418 I\\'m a teapot', 421 => 'HTTP/{version} 421 Misdirected Request', 422 => 'HTTP/{version} 422 Unprocessable Entity', 423 => 'HTTP/{version} 423 Locked', 424 => 'HTTP/{version} 424 Failed Dependency', 426 => 'HTTP/{version} 426 Upgrade Required', 428 => 'HTTP/{version} 428 Precondition Required', 429 => 'HTTP/{version} 429 Too Many Requests', 431 => 'HTTP/{version} 431 Request Header Fields Too Large', 451 => 'HTTP/{version} 451 Unavailable For Legal Reasons', 500 => 'HTTP/{version} 500 Internal Server Error', 501 => 'HTTP/{version} 501 Not Implemented', 502 => 'HTTP/{version} 502 Bad Gateway', 503 => 'HTTP/{version} 503 Service Unavailable', 504 => 'HTTP/{version} 504 Gateway Timeout', 505 => 'HTTP/{version} 505 HTTP Version Not Supported', 506 => 'HTTP/{version} 506 Variant Also Negotiates', 507 => 'HTTP/{version} 507 Insufficient Storage', 508 => 'HTTP/{version} 508 Loop Detected', 510 => 'HTTP/{version} 510 Not Extended', 511 => 'HTTP/{version} 511 Network Authentication Required']; public $JComponentTitle = NULL; public $item_associations = NULL; protected $document = class Joomla\\CMS\\Document\\JsonDocument { public $title = 'Joomla 5.2-dev at vmubu02 - Administration'; public $description = NULL; public $link = ''; public $base = ''; public $language = 'en-gb'; public $direction = 'ltr'; public $_generator = 'Joomla! - Open Source Content Management'; public $_mdate = ''; public $_tab = '\\t'; public $_lineEnd = '\\n'; public $_charset = 'utf-8'; public $_mime = 'application/json'; public $_namespace = ''; public $_profile = ''; public $_scripts = [...]; public $_script = [...]; protected $scriptOptions = [...]; public $_styleSheets = [...]; public $_style = [...]; public $_metaTags = [...]; public $_engine = NULL; public $_type = 'json'; protected $mediaVersion = '92d725'; protected $factory = class Joomla\\CMS\\Document\\Factory { ... }; protected $preloadManager = class Joomla\\CMS\\Document\\PreloadManager { ... }; protected $preloadTypes = [...]; protected $webAssetManager = class Joomla\\CMS\\WebAsset\\WebAssetManager { ... }; protected $_name = 'joomla' }; protected $language = class Joomla\\CMS\\Language\\Language { protected $debug = FALSE; protected $default = 'en-GB'; protected $orphans = [...]; protected $metadata = [...]; protected $locale = NULL; protected $lang = 'en-GB'; protected $paths = [...]; protected $errorfiles = [...]; protected $used = [...]; protected $counter = 34; protected $override = [...]; protected $localise = NULL; protected $helper = NULL; protected $basePath = NULL; protected $catalogue = NULL; protected $parserRegistry = NULL; protected $strings = [...]; protected $transliterator = NULL; protected $pluralSuffixesCallback = [...]; protected $ignoredSearchWordsCallback = NULL; protected $lowerLimitSearchWordCallback = NULL; protected $upperLimitSearchWordCallback = NULL; protected $searchDisplayedCharactersNumberCallback = NULL }; protected $identity = class Joomla\\CMS\\User\\User { protected $isRoot = TRUE; public $id = 449; public $name = 'Richard'; public $username = 'rfadmin'; public $email = 'admin@richard-fath.de'; public $password = '$2y$10$m2q445OmCGAixhOgju.UaeUcOt/9.KR3kGTXQtBy.U3Pu/0EJjRgu'; public $password_clear = ''; public $block = 0; public $sendEmail = 1; public $registerDate = '2025-04-06 12:25:24'; public $lastvisitDate = '2025-04-06 12:34:09'; public $activation = '0'; public $params = ''; public $groups = [...]; public $guest = 0; public $lastResetTime = NULL; public $resetCount = 0; public $requireReset = 0; public $typeAlias = NULL; public $otpKey = ''; public $otep = ''; public $authProvider = ''; protected $_params = class Joomla\\Registry\\Registry { ... }; protected $_authGroups = [...]; protected $_authLevels = [...]; protected $_authActions = NULL; protected $_errorMsg = NULL; protected $_errors = [...] }; private ${Joomla\\CMS\\Application\\WebApplication}userFactory = class Joomla\\CMS\\User\\UserFactory { private $db = class Joomla\\Database\\Mysqli\\MysqliDriver { ... } }; protected $docOptions = []; public $scope = 'com_ajax'; protected $clientId = 1; protected $messageQueue = []; protected $name = 'administrator'; protected $profiler = class Joomla\\CMS\\Profiler\\Profiler { protected $start = 1743942857.7924; protected $prefix = 'Application'; protected $buffer = [...]; protected $marks = [...]; p
PHP  14. Joomla\\Component\\Content\\Administrator\\Model\\ArticleModel->save($data = ['catid' => 9, 'title' => 'About', 'introtext' => '<p>This tells you a bit about this blog and the person who writes it.</p><p>When you are logged in you will be able to edit this page by selecting the edit icon.</p>', 'fulltext' => '', 'id' => 0, 'ordering' => 0, 'created_user_id' => 449, 'created_by_alias' => 'Joomla', 'alias' => 'about', 'language' => '*', 'associations' => [], 'metakey' => '', 'metadesc' => '', 'featured' => 0, 'state' => 1, 'images' => '', 'access' => 1]) /joomlaroot/plugins/sampledata/blog/src/Extension/Blog.php:716, referer: https://www.joomla-52-dev.vmubu02.vmnet2.local/administrator/index.php
PHP  15. Joomla\\Component\\Content\\Administrator\\Model\\ArticleModel->featured($pks = 1, $value = 0, $featuredUp = NULL, $featuredDown = NULL) /joomlaroot/administrator/components/com_content/src/Model/ArticleModel.php:784, referer: https://www.joomla-52-dev.vmubu02.vmnet2.local/administrator/index.php
PHP  16. Joomla\\CMS\\Table\\Table->reorder($where = *uninitialized*) /joomlaroot/administrator/components/com_content/src/Model/ArticleModel.php:946, referer: https://www.joomla-52-dev.vmubu02.vmnet2.local/administrator/index.php
PHP  17. Joomla\\Database\\Mysqli\\MysqliQuery->selectRowNumber($orderBy = '`ordering`', $orderColumnAlias = 'new_ordering') /joomlaroot/libraries/src/Table/Table.php:1487, referer: https://www.joomla-52-dev.vmubu02.vmnet2.local/administrator/index.php
PHP  18. Joomla\\Database\\DatabaseQuery->__get($name = 'mariadb') /joomlaroot/libraries/vendor/joomla/database/src/Query/MysqlQueryBuilder.php:221, referer: https://www.joomla-52-dev.vmubu02.vmnet2.local/administrator/index.php
PHP  19. trigger_error($message = 'Undefined property via __get(): mariadb in /joomlaroot/libraries/vendor/joomla/database/src/Query/MysqlQueryBuilder.php on line 221', $error_level = 1024) /joomlaroot/libraries/vendor/joomla/database/src/DatabaseQuery.php:485, referer: https://www.joomla-52-dev.vmubu02.vmnet2.local/administrator/index.php

System information (as much as possible)

5.2-dev

Additional comments

The culprit is the recent update of the database framework, which includes an error made by me with my PR joomla-framework/database#335 ,

I have already provided a fix in the framework: joomla-framework/database#337

As soon as that is merged there and released and a PR is made to pull that into the CMS, we can close this issue.