[Bug 44120] Steam Big Picture mode fails to start, it shows a black screen (d3d10, d3d11, more)

https://bugs.winehq.org/show_bug.cgi?id=44120

--- Comment #3 from Aaron Franke  ---
You are correct that buttons work despite not being visible and sound does
actually work. I did not try clicking on the blackness to see if anything
happened, and I did not hear Steam Big Picture's ambient sounds. I apologize
for not testing thoroughly enough, but hopefully the logs and their reports of
unimplemented functions helps the Wine devs fix Steam Big Picture!