Download addon again from site, it should be latest 2.80 version compilatible

could you send a picture of viewport from blender?
also try unabling "Auto Smooth"

If it looks rotated in blender without sequences and imported straight from model .smds, it's actual looking of it

If you go to edit mode is it gets normal position?

Can you remade idle sequence? Also try to refresh $definebones

Import smds not .qc, maybe model will get standard position

Really, it maybe idle sequences problem. Try to import it without sequences

I rigged model, ported to engine. When I spawn my model in GMod seems like nothing wrong but when I start manupilate bones model just dissappears in certain angles. If bones not rotated model works good. So, how to fix this?

Screenshots:
https://imgur.com/a/RzcaUJz

how looks
https://imgur.com/a/MZT9vGz
https://imgur.com/a/k9w46Le

When I rotated model
https://imgur.com/a/Oh4SZBL
https://imgur.com/a/V3uESc3