To be honest, I have no idea what's happening. Maybe you're using too high flags and the game messes everything up. Before crashing, in Jack's house, the ArmsItem.tsc is not working either. Something is wrong with the data. Again, are you using flags higher than 8000?
Then you might have overwritten data that normally holds map names & properties, and also TSC.
I don't think you can fix this without replacing all super-high flags with lower ones.
Sorry.