Weapon change.

Well, if you follow the tutorial, which I think is on this site, and download the files that forum members have saved, then all the programs will work - yes, it's very tedious, but it works... Read it more carefully, and in general, if there's some kind of error there or something, you need to post screenshots so that it's clear

Added 2 minutes ago
P.S. Ah, it just doesn't launch... that's strange

Added 1 minute ago
Well, as an option... Maya is only needed for importing into the game - if you prepared the file in Blender, 3ds Max, or somewhere else, make an FBX and post it here with a request to reformat it into a game file...