It gets to 'possible unused room textures: 32', then 'this program has encountered...'

I tried TRFix to look at the project, but it crashes trying to load it. Heck, it even crashes trying to load my older ones that I know convert, so I do not put too much weight on what it is saying.
I really do not want to split my level... but what could be wrong?

Thanks for any tips,
Jon