like others have said I'm u able to report a bug. Whenever I get to the upload screenshot portion it says an error as occurred and to contact an administrator. 

The bug I'm trying to report is the guardians might achievement is stuck. 

I got to 99% and it won't move any more. Since getting to 99% I've killed easily 100 more with all 3 melee weapons. 

I also stuck at 155/300 . it just not registering my kill to the steam achievement .