If i find a situation where GSB is throwing an error due to a mod - but you can not determine which one, I run through the following process.
Step 1: Back to first principles.
Open \Gratuitous Space Battles\data\installs
In there you will find all the install files for Campaign / DLC & Mods.
Rename every mod.txt file to mod.off - for example:
unit.txt -> unit.off
Classic DNs.txt -> Classic DNs.off
Step 2: Move or delete your designs.
Open \My Documents\My Games\GratuitousSpaceBattles\ships
In there you will find all your designs for the various factions.
Either delete them or move them somewhere else till you solve the problem.
Step 3: Run GSB.
In theory, GSB will not open any mods and there will be no ship designs from mods to trip it up.
From there you reintroduce each mod (by renaming .off to .txt) one at a time and find out which one is causing the error.
Once you have found the mod its then a case of trying to find out what is causing the problem
(my guess is a hull file)