ExpandPHP Fatal error: Uncaught ErrorException: Warning: Undefined property: Symfony\Component\VarDumper\Caster\CutStub::$cache_locking in \vendor\smarty\smarty\libs\sysplugins\smarty_internal_template.php:737
Stack trace:
#0 [internal function]: Smarty_Internal_Template->__destruct()
#1 {main}
thrown in ************\vendor\smarty\smarty\libs\sysplugins\smarty_internal_template.php on line 737
I had this same error on Prestashop 8.2.1, the bug is still present.
You find the bug fix at this link: https://github.com/PrestaShop/PrestaShop/pull/37928/files
Sadly I still have the Module Manager stuck (can't search, can't expand and browse all modules). Now I try to disable or uninstall all third party modules.
Edit: finally it was Firefox. Everything is fine in Chrome. I am not sure why I have this issue.