Hello, I have this error: Class 'Joomla\CMS\Form\Field\ListField' not found I have joomla 3.10. JaFlix
Hi
It looks like part of template or extension on your site which is updated for Joomla 5 and you're using old Joomla 3 so it throws this error.
I recommend you to upgrade your site to Joomla 4/5.