[LDCad] Crash LDCad looking for brick 3940

[Roland Melkert]

Had the same, found the issue to be in a part I created, sorry.. 
Updated 19789s01, it had some triangles/quads in edge color (24) instead of 16, this causes LDCad to crash for some reason.
If you update this subfile the crash should be gone.

That should not crash anything, so it's a bug.

I fixed it in the 1.7 Beta 1 code.