General Questions/New to Joomla! 5.x • Error "Cannot instantiate abstract class" after Joomla rollback from 5.1.0 to 5.0.3

Hello,

I recently encountered an issue with my Joomla site and am seeking your assistance. I upgraded my site to Joomla 5.1.0 but had to roll back to 5.0.3 due to translation issues in the YooTheme Pro contact page. After rolling back, I began experiencing a persistent error that prevents me from logging into the backend:

Cannot instantiate abstract class Joomla\Module\Login\Administrator\Helper\LoginHelper

Here’s a brief rundown of what happened:

I updated to Joomla 5.1.0 but then restored back to 5.0.3 because the YooTheme Pro's translation was causing issues on the contact page.
Post-update, I had some problems and ended up deleting the

/public_html/administrator/cache/autoload_psr4.php

file.
After performing the rollback, the above error started appearing.
I've cleared everything in the tmp and cache directories, but the issue persists.

Is it possible that the database was updated during the 5.1.0 upgrade and that these changes were not manually reverted during the rollback, causing incompatibility with the current Joomla 5.0.3 CMS? Any insights or recommendations on how to troubleshoot this issue and regain access to my admin panel would be greatly appreciated.

Thank you in advance for your help!

Best regards,
MrNordio

Statistics: Posted by mrnordio — Fri May 03, 2024 5:05 pm

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