Hello everybody!
I was last week trying to resolve an error after upgrading Moodle to version 3.8.2+ stable.
The error occurs on the list of users enrolled in the course when I click the Register User button. Displays a blank alert popup with the title "SyntaxError".
When I activate the error display for developers and display some more details of the problem:
SyntaxError: Unexpected token < in JSON at position 0 at parse (<anonymous>) at https://sub.domain.com.br/lib/javascript.php/1587762995/lib/jquery/jquery-3.4.1.min.js:2:78358 at l (https://sub.domain.com.br/lib/javascript.php/1587762995/lib/jquery/jquery-3.4.1.min.js:2:78475) at XMLHttpRequest.<anonymous> (https://sub.domain.com.br/lib/javascript.php/1587762995/lib/jquery/jquery-3.4.1.min.js:2:81117)
I also looked at the browser inspector:
Query.Deferred exception: Unexpected token < in JSON at position 0 SyntaxError: Unexpected token < in JSON at position 0
at parse (<anonymous>)
at https://sub.domain.com.br/lib/javascript.php/1587762995/lib/jquery/jquery-3.4.1.min.js:2:78358
at l (https://sub.domain.com.br/lib/javascript.php/1587762995/lib/jquery/jquery-3.4.1.min.js:2:78475)
at XMLHttpRequest.<anonymous> (https://sub.domain.com.br/lib/javascript.php/1587762995/lib/jquery/jquery-3.4.1.min.js:2:81117) undefined
k.Deferred.exceptionHook @ jquery-3.4.1.min.js:2
I thought there was an error in the upgrade, because I made it from 3.3 (PHP 7.1, MySQL 5.7 MariaBD, SSL Active) to 3.8.2. Then I upgraded again, version by version, 3.4, 3.5, etc., up to 3.8.2. And I repeated the test on the subscribers list screen in each version I updated. Only in version 3.8.2 the problem happens.
The only solution suggestion I found here on the forum was this:
https://moodle.org/mod/forum/discuss.php?d=394922
He suggests disabling the Javascript cache. However, as the author said, it creates other problems, as we need the Javascript cache active for a good functioning.
I would like to know if anyone else has this problem, if they managed to solve another problem and if there is a correction forecast for this.
The definitive solution for me so far was not to use the upgrade to 3.8.2, keeping the 3.7 stable active where the problem does not occur.
Translated with Google translate from Brazilian Portuguese.