custom weapon doesnt render outer layer

[duocpk]

my custom weapon texture doesnt render correctly ingame
im using blender v2.81
how it look:
https://imgur.com/ge32YF1
https://imgur.com/2X6OY3B
mesh:[url]https://www.mediafire.com/file/0cyy7f7d ... h/file[url]
please help me!