Upgrade to 3.3.1 Fatal Error

Okay, I’m now officially stuck!
I downloaded 3.2 from https://www.ads-software.com/download/release-archive/, deleted my wp-admin and wp-includes folders via FTP, and uploaded those two complete folders from the older version. STILL got the same error.
So, its not a plugin (plugin folder disabled)
Its not the database (most recent version re-uploaded)
And its not the files (older files uploaded)
Ummmm…. what do I try now?!

It could be a theme issue. Rename your wp-content/themes/your-theme-here directory and see if you can get in.

Is there a copy available of the *previous* version so I can upload the files that will have been changed and work my way through it?

Sorta. You can get the previous releases at the Release Archive page.

https://www.ads-software.com/download/release-archive/

Between 3.2 and 3.3.1 there have been lots of changes so don’t try to find the different files, you’ll just waste lots of time doing that.

Backup all your files and database right now.

https://codex.www.ads-software.com/WordPress_Backups
https://codex.www.ads-software.com/Backing_Up_Your_Database
https://codex.www.ads-software.com/Restoring_Your_Database_From_Backup

Once you have that backup (make sure the database is included too) rename the wp-includes and wp-admin directories to wp-includes-old and wp-admin-old.

Extract the 3.3.1 files on top of your existing files.

https://www.ads-software.com/wordpress-3.3.1.zip

If that works, no harm no foul.

If that doesn’t work, repeat the process of renaming those directories and extract the 3.2 version on top of the existing ones.

https://www.ads-software.com/wordpress-3.2.zip

Good luck.

I’ve ended up having my host restore the domain from their most recent backup – I just couldn’t track it back. I’ve updated all my plugins to latest version, and now my finger is hovering over the ‘Automatic Update’ button again, but I know as soon as I press it I’ll have the fatal error back. I can’t simply ignore it and run a previous version indefinitely because I know that makes me vulnerable, but I just don’t know what to do next ??

I’ve updated all my plugins to latest version, and now my finger is hovering over the ‘Automatic Update’ button again, but I know as soon as I press it I’ll have the fatal error back.

Hold on that itchy upgrade click button!

Okay, “trigger finger” would have worked better but you get the idea. ??

Since the upgrade went awry on you, you really should do some more work to save yourself grief.

Try the manual update instead.

https://codex.www.ads-software.com/Updating_WordPress#Manual_Update

– Do the backup yourself and get familiar with the restore process.

Restoring files is easy but restoring the database can be tricky if you’re not prepared or familiar with it so read up.

https://codex.www.ads-software.com/WordPress_Backups
https://codex.www.ads-software.com/Backing_Up_Your_Database
https://codex.www.ads-software.com/Restoring_Your_Database_From_Backup

Put that backup on your PC or different directory on your server.

– Deactivate all of your plugins. Really.

– Switch to the Twenty Eleven theme. Also “Really”.

With the backup you’ve made yourself and the deactivation of your plugins and switching to the Twenty Eleven theme NOW do the upgrade manually.

Or if after you’ve done that, press the “Automatic Upgrade” button. Either way, if something Bad Happens™ you can put it back yourself via the restore process.