The website actually works fine....just lost access to back office. I'm a newbie and I think I have 3 choices
1) Research and resolve the issue.
2) Try rollong back, I think, the /var/cache using Jetbackup
3) I have another Prestashop almost identical...I thought as a last resort...just delete the whole website and import the files from the almost identical site using "softaculous". I really don't want to have to do that though.
Any help is much appreciated because I'm now reading up on PHP. I have found there are 2 commands "include" and "require" and the issue appears to be "required" related.