Solve 500 error in ATK Framework Application

We have software built with the ATK framework http://www.atk-framework.com. The program throws a 500 error when clicking links on the main menu, but there are no errors displaying in the cpanel error log. Once the error starts, it takes hours before the program becomes usable again. We need someone to figure out what's causing the 500 error and repair the problem. The program is very simple and only has 4 tables. This is a rush job and needs to be completed within 24 hours.