https://bugs.winehq.org/show_bug.cgi?id=47778
--- Comment #4 from Andrew Schott andrew@schotty.com --- I figured out what was causing me grief. Blizzard's code hates symlinks. I have segregated off my game data in every prefix, and symlink it in where appropriate. So in this case I have a blizzard_games folder elsewhere that I symlinked each game in where BNet defaults the install to. I removed these symlinks and instead mapped a drive letter to it, and lastly pointed BNet to the new drive letter. In game shop works now.
I have a few prefixes that all were experiencing the black screen issue, and all are fixed now by getting away from the symlinks.