Not sure why and I vaguely remember something very similar occurring before and cant really remember what I did to fix the crashing. Does anyone else remember how to get this installed on a Mac system?
I remember a Mod issue that used to crash Mac OS, If I recall it had to do with something like; file name over 8 x 3 in the truetile image name.. Or a missing image file in truetile. I also remember something having to do with the background color of srites, but I don't think the last caused crashes.
Sorry for late response, but maybe someone will still be looking at the root cause. There were two problems.
1. Copying contents of the file on Mac didn't replace contents of truetile folder as expected and this caused crash. Solution to this problem is to apply contents of this folder manually. Original post is here
https://www.unrealworld.fi/forums/index.php?topic=147.msg19551#msg19551.
2. Image files for objects (in truetile folder) had wrong background on Mac and it had something to do with alpha color and neutral background specified by corner pixel. It didn't cause crash as far as I remember. Original post is here
https://www.unrealworld.fi/forums/index.php?topic=4712.msg15700#msg15700.