Now it's only a few lines of code, a NULL level and one entity ("tile3.mdl"). If you remove the empty skin(s) (or load "tile3b.mdl") the crash is gone. Otherwise, after 5-6 starts at the latest the error should appear.
Tried about 20 times with both models ('tile3.mdl' and 'tile3b.mdl'), but it did not crash for me.
