I can't reproduce the issue. I see the page.

But I don't know what table that's in

Presumably table #__content column metadata.

#3 plugins/system/jsntplframework/includes/core/j3x/jsntplviewlegacy.php(398): ContentModelArticle->getItem()

Keep your JSN template framework up-to-date and/or ask in their forum respectively.

@truelai Can it be that the issue has been meanwhile solved e.g. by updating some 3rd party component? I can't reproduce it anymore using the links in the description. Yesterday I could reproduce it, and the error was shown in a box with some text about falang extension at the bottom.

Very sorry @richard67. I rolled back the snapshot. I can re-deploy it in its broken state if you want to check it out.

No, just good to know about current status. But if you have an SQL export of the database when it was broken, that could be useful. And if you find out that it is related to a 3rd party extension, please let us know, too. Please check all your 3rd party extensions if they are up to date and if not, update them. Then check again if the error is there and let us know the result. It would be useful if you had a local of your site in broken state so you can test.

@truelai can you give us the value of the metadata field of the broken article? It seams that the json is broken.

I am unable to open the article in the CMS. I get:

Error decoding JSON data

@HLeithner @richard67 @ReLater, I have redeployed the broken version. You can see the error now. Please let me know when you've observed the bug.

Can you open phpmyadmin so similar tool and copy the raw data from the #__content table?

This what you're looking for?

mysql> SHOW COLUMNS FROM ptf5s_content;
+------------------+---------------------+------+-----+---------------------+----------------+
| Field            | Type                | Null | Key | Default             | Extra          |
+------------------+---------------------+------+-----+---------------------+----------------+
| id               | int(10) unsigned    | NO   | PRI | NULL                | auto_increment |
| asset_id         | int(10) unsigned    | NO   |     | 0                   |                |
| title            | varchar(255)        | NO   |     |                     |                |
| alias            | varchar(400)        | NO   | MUL |                     |                |
| introtext        | longtext            | NO   |     | NULL                |                |
| fulltext         | longtext            | NO   |     | NULL                |                |
| state            | tinyint(3)          | NO   | MUL | 0                   |                |
| catid            | int(10) unsigned    | NO   | MUL | 0                   |                |
| created          | datetime            | NO   |     | 0000-00-00 00:00:00 |                |
| created_by       | int(10) unsigned    | NO   | MUL | 0                   |                |
| created_by_alias | varchar(255)        | NO   |     |                     |                |
| modified         | datetime            | NO   |     | 0000-00-00 00:00:00 |                |
| modified_by      | int(10) unsigned    | NO   |     | 0                   |                |
| checked_out      | int(10) unsigned    | NO   | MUL | 0                   |                |
| checked_out_time | datetime            | NO   |     | 0000-00-00 00:00:00 |                |
| publish_up       | datetime            | NO   |     | 0000-00-00 00:00:00 |                |
| publish_down     | datetime            | NO   |     | 0000-00-00 00:00:00 |                |
| images           | mediumtext          | NO   |     | NULL                |                |
| urls             | mediumtext          | NO   |     | NULL                |                |
| attribs          | varchar(5120)       | NO   |     | NULL                |                |
| version          | int(10) unsigned    | NO   |     | 1                   |                |
| ordering         | int(11)             | NO   |     | 0                   |                |
| metakey          | mediumtext          | NO   |     | NULL                |                |
| metadesc         | mediumtext          | NO   |     | NULL                |                |
| access           | int(10) unsigned    | NO   | MUL | 0                   |                |
| hits             | int(10) unsigned    | NO   |     | 0                   |                |
| metadata         | mediumtext          | NO   |     | NULL                |                |
| featured         | tinyint(3) unsigned | NO   | MUL | 0                   |                |
| language         | char(7)             | NO   | MUL | NULL                |                |
| xreference       | varchar(50)         | NO   | MUL |                     |                |
| note             | varchar(255)        | NO   |     |                     |                |
+------------------+---------------------+------+-----+---------------------+----------------+
31 rows in set (0.00 sec)

@truelai No. Show columns gives the structure. We want to know the data.

SELECT * FROM `ptf5s_content` WHERE `id`=123;

with 123 being the id of the article which has that problem.

@truelai No. Show columns gives the structure. We want to know the data.

SELECT * FROM `ptf5s_content` WHERE `id`=123;

with 123 being the id of the article which has that problem.

Please see to the below file:
mysql.txt

I think this is the string that can't be loaded:

{"robots":"","author":"","rights":"","xreference":""}

@truelai your data is broken in this article. the field doesn't end after {"robots":"","author":"","rights":"","xreference":""} the field includes a tags= the complete field is

{"robots":"","author":"","rights":"","xreference":""}
tags=

if the problem is only in this article you can do

update `ptf5s_content` set metatdata="" WHERE `id`=82;

if all articles are broken you should look first if there are metadata that you still need.

select id,metadata from ptf5s_content

@HLeithner - Thanks very much. This is the fix!

Any idea why this happened? It was after an upgrade from 3.5.x and from php7.0 to 3.9.16 and php7.3

I also see a ton of broken sites online that seem to be affected by the same bug (found while searching for solutions)? Makes me think it's php related and all the sites that are broken may be due to shared hosts doing php updates?

It's possible that something has changed on the json parser... I'm closing this if there is another problem you can open this issue again or create an new issue.