Code:
Database error in vBulletin 4.2.0:

Invalid SQL:

        SELECT *
        FROM navigation
        WHERE state &  = 0
        ORDER BY navtype, displayorder;

MySQL Error   : You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near '= 0
        ORDER BY navtype, displayorder' at line 3
Error Number  : 1064
This error was fixed by re-uploading all the upgrade files and running it in a new browser. I used Firefox the first time and it just hung on the upgrade screen, breaking the database.

The second time around I used Chrome and the process worked.