Forum Problem upgrading to 4.02 from 4.0.0
 

I copied the upgrade files from the ZIP into the correct directories, and everything completely broke. Even the admin panel wouldn't open, but it did work in another tab that I already had open so I could shut my forum down.

The error message:

Fatal error: Call to undefined method vB_Input_Cleaner::utf8_clean() in /home/content/k/i/m/kimianjeff/html/forum/includes/class_friendly_url.php on line 552

I copied the original files back in and have it working as 4.0.0, but did I mess something up in the installation of the files, or is there something not working in them?