CMS Unable to fix blank CMS screens - error in controller.php
 

I've upgraded my forums from v3.7 to 4.0PL1 Suite. The upgrade went well, and both the forums and blogs are working correctly.

I'm having trouble with the CMS... at first all I was getting was blank screens whenever I tried to access the CMS main page, or if I tried to view (via the admincp) one of the built in CMS posts that are created on the upgrade.

I went through the checklist and fixes for blank screens, and when I turned on the error reporting for PHP, the CMS screen shows the following error:

Fatal error: Call to a member function setSegments() on a non-object in /vservers/mysite.com/forums/vb/controller.php on line 242

I tried re-uploading a clean set of files instead of doing an overwrite like I did with the upgrade and I still get the same error. I tried searching here but couldn't find anything close to that error. I don't have any mods installed.

Thanks for any assistance that anyone is able to provide.