Trying to open one of our 1.1.2 projects in Designer 1.2.2 Build 48 and encountering the following error:

An unexpected error occurred
Please help us make Designer better by reporting this error to the Designer forums
TypeError: 'undefined' is not an object
Restart Exit Designer
Based on other posts I've found in the forums, I'm guessing the problem lies in one of our class definitions, but I have no indication of where the problem lies. Is there any way to run Designer in a debug or enhanced logging mode so that I can actually see where the error is occuring?