Tried manually updating prestashop to the latest version, but after no success I deleted it all and re-instated my original zip file back up + database to try to roll back to at least a working version. However even though that backup version worked fine now all I get is error 500 and no access to the control panel. I've contacted my host and they've tested both the SSL certificate and checked through all the permissions to make sure that's not the issue, and their tech team has narrowed it down to the htaccess file. If I rename it my site gives a 404 error instead.
I can see from previous posts that people have deleted the htaccess file and cleared the cache to re-generate it, but how do you do that without access to the back office control panel? Is there a manual way to turn off friendly-urls which often causes this problem?
I'm using this article for reference for trouble shooting: https://www.prestashop.com/en/blog/the-500-internal-server-error-explained-solved
Any help much appreciated! I've tried both my webhosts code guard site auto back up and manual back ups to fix this but nothing is returning the original working version.
EDIT
Fixed it by enabling debug and finding a database connection issue. Turns out I'd changed the database password without remembering to put it in my edit log and that caused it to misconnect. Remember to write down everything you did folks!!