Not sure this is a bug, I too use a card that uses this driver. I believe AMD isn't fully supporting it anymore, and something about it marks it as old and out of date from game's viewpoint.
Other games I play, notably Hunt Showdown, have added new stuff that apparently make use of graphical features that these old cards may not fully support, or at least are not given support by AMD.
Hopefully the devs can be accommodating to older technologies, or community-based plugins arise that fill in the gaps left open by AMD.