"File does not contain expected contents" in register.php
 

I've upgraded to 3.8.2 and since then, after registration, the user is not logged in.

I tried registering with the original Style from vBulletin, and the same error.

So, I checked the "Suspect File Versions", and found this:

register.php File does not contain expected contents

I've re-uploaded the original register.php file from 3.8.2 in ASCII but keep seeing the same message.

I've also disabled all hooks from config.php and the "File does not contain expected contents" is still there..

What should I check now?