https://bugs.winehq.org/show_bug.cgi?id=38815
--- Comment #7 from Rosanne DiMesio dimesio@earthlink.net --- I can't test the pokerstars.es client because it detects that I'm in the United States. It installs fine, but won't let me login with a pokerstars.com account or create an account on pokerstars.es.
The client available from pokerstars.com, which is not the same as the one tested in comment 1, does have links for Challenges and Leaderboards in the right sidebar. Those both work on my system. The windows are a bit slow to load, but the info does eventually appear. I'm not familiar with what it's supposed to look like, but there's nothing obviously wrong, and it's definitely not just a black screen.
https://www.pokerstars.com/poker/download/ sha1sum PokerStarsInstall.exe fde6cc21e34373b78ef30fc6ec77fdd3da8e4b76 PokerStarsInstall.exe
I don't know if you can test the client from https://www.pokerstars.com/poker/download/, as there appear to be geographic restrictions on various clients, but give it a try, and see if it has the same problem.