Using Akeeba Backup I created a copy of my Joomla 3.10.12 website: FBCFalun.org. I fully restored it to another domain I own as a sandbox of my site. I then successfulyy upgraded the sandbox to Joomla 4.3.3. I use a Shape5 template that had issues with a menu plugiin that I was finally able to get from Shape5 so that I could upgrade the sandbox site to Joomla 4.3.3.
Having gotten the sandbox upgraded and working yesterday I proceeded to upgraded my main site (FBCFalun.org) to 4.3.3. After the upgrade the website failed to load correctly. I could access the backend. I changed the default template to Cassiopia and the frontend began working, but since the site was built on the Shape5 menu plugin nothing on the site could be accessed.
After multiple attempts to address the template plugin issue I decided to restore the site back to Joomla 3.10.12. I had made a backup just prior to upgrading to 4.3.3.
Today I used Akeeba Backup 9.6.2, installed on FBCFalun.org, to restore the backup I made yesterday of the 3.10.12 version of the site.
I opened Manage Backups from the Akeeba Control Pannel, selected yesterday's 3.10.12 backup and selected restore. Everything proceeded as expected. I selected 'Remove The Installation Directory" and then clicked on "Visit your site's front end." Actually, I right clicked and selected enter in a new tab and got the attached error message on the website frontpage.
I tried logging into the backend and received the this message:
An error has occurred.0 Class 'Joomla\Console\Application' not found
Return to Control Panel
For now I have my website redirecting to my sandbox which is working fine.
I am at a total loss as to what happened and how to fix this.
Mike K
p.s For some reason, I was not able to insert an image into my post because I couldn't find any way to upload in image through the image manager.