Game stopped working

I donwloaded the demo, enjoyed it, and bought the game + tribe expansions from steam. Worked fine. Then i tried the GBS Enchanged mod 0.99 BETA, and it worked fine (i moved copy of the data directory to safety). Then i deleted data, and moved the old directory back, to restore original game. Now the main menu background loads, and music starts, and then game crashes to desktop. Reinstalling or repairing game files through steam does no difference.

i wonder if it is the saved ship designs using modded weapons and hulls, but i can find where they are stored…

If it helps at all, my saved ship files (and other things) are in
\My Documents\My Games\GratuitousSpaceBattles

yep, deleting ships helped. Thank you:)