can you activate debugging and post the backtrace please?

An error has occurred.
0 Argument 2 passed to JAdapterInstance::__construct() must be an instance of JDatabaseDriver, instance of Joomla\Database\Mysqli\MysqliDriver given, called in C:\wamp\www\j4new\libraries\joomla\base\adapter.php on line 153

Call stack
--
# | Function | Location
1 | () | JROOT\libraries\joomla\base\adapterinstance.php:47
2 | JAdapterInstance->__construct() | JROOT\libraries\joomla\base\adapter.php:153
3 | JAdapter->setAdapter() | JROOT\libraries\src\Updater\Updater.php:237
4 | Joomla\CMS\Updater\Updater->getUpdateObjectsForSite() | JROOT\libraries\src\Updater\Updater.php:156
5 | Joomla\CMS\Updater\Updater->findUpdates() | JROOT\administrator\components\com_installer\Model\UpdateModel.php:271
6 | Joomla\Component\Installer\Administrator\Model\UpdateModel->findUpdates() | JROOT\administrator\components\com_installer\Controller\UpdateController.php:111
7 | Joomla\Component\Installer\Administrator\Controller\UpdateController->find() | JROOT\libraries\src\MVC\Controller\BaseController.php:728
8 | Joomla\CMS\MVC\Controller\BaseController->execute() | JROOT\libraries\src\Dispatcher\ComponentDispatcher.php:146
9 | Joomla\CMS\Dispatcher\ComponentDispatcher->dispatch() | JROOT\libraries\src\Component\ComponentHelper.php:383
10 | Joomla\CMS\Component\ComponentHelper::renderComponent() | JROOT\libraries\src\Application\AdministratorApplication.php:117
11 | Joomla\CMS\Application\AdministratorApplication->dispatch() | JROOT\libraries\src\Application\AdministratorApplication.php:160
12 | Joomla\CMS\Application\AdministratorApplication->doExecute() | JROOT\libraries\src\Application\CMSApplication.php:241
13 | Joomla\CMS\Application\CMSApplication->execute() | JROOT\administrator\includes\app.php:63
14 | require_once() | JROOT\administrator\index.php:36

I can't confirm this. Is this a new installation with git or alpha?

If git did you removed the autoloader? And die composer install?

git.

yes, i removed both 2 autoloaders.

Composer install, and composer update.

fresh install? And the problem occurs on administrator/index.php?option=com_installer&view=update ?

@810 which two autoloaders did you remove? I know only about one to be removed, don‘t remember name right now. And why composer update? We shall do only composer install and then npm install.

Ok, i removed everything on the dir, now its working. Looks there was a file that doesn't be there.

I do composer update, because im working on database changes, so i wanted to sure that i have the latest database framework release.

@810 Regarding composer update: If you want to pull in only the changes in the database package you can use composer update joomla/database. I guess you know that already, but just in case if not I thought I post this info here.