If you are running 4.2.0, then you CANNOT just upload the 4.2.2 security patch. The 4.2.2 security patch is ONLY for users running 4.2.2. You would need to follow the instructions here to secure your site - http://www.vbulletin.com/forum/node/4024574 You should put back your original 4.2.0 files and then patch your site via those instructions.