Forum Fatal Error
 

I installed a modification, but it resulted in a fatal error.

I can access the Admin CP, but I can't access the forum nor anything in Plugins & Products, so I can't disable it. (This happened a little while ago with another mofication, but I was still able to access Manage Products to disable it.) Unfortunately, I am by no means an expert on server work. I have FileZilla, but I have no idea what to do.

All I know how to do is take backups. Additionally, I happen to be the only one online right now.

Anyone willing to help? :(

Also, yes, I know that modification discussion goes on vBulletin.org Forum, but this isn't about the modification, it's about fixing the error. :)