Hi,

My forum (5.6.4) was running fine after it got upgraded. As soon as the upgrade process completed, I entered the admin cpanel and did all maintenance tasks it suggested, all of them were done successfully. I got some rest for few hours, and came back later to find the forum down sadly. Whenever I try to access It,

It says:
" A System Error has occurred.
The software is experiencing a systems error.
You should attempt to repeat your last action. If this error occurs again, please contact the site administrator.".

I enabled the debug mode (in the config.php file which is in the root folder of the forum) to see the exact cause of the error, I got the following when I try to access the forum:

"Error :Cannot use database myforum_db_name on line 1215 in phar:///home/kjakja/public_html/forums/core/vb/vb.phar/database.php '

Please help to figure out what causes this issue, and get it resolves, It has been down for more that 10 hours so far.

Best regards

1. vBulletin Version - 5.6.4
2. PHP Version - 7.4
3. MySQL Version - 5.6.49-cll-lve
4. Any Addons installed. No addons at all.
5. Does the issue occur in a default style? Forum Not accessible.
6. Does the issue occur using the English language provided? Forum Not accessible.
7. Browser and Browser version used. All browsers.
8. Did you clear the browser cache and did the error continue?