oncologist: To fix this, I had to uninstall, RESTART, and re-install GOG Galaxy. Re-installing without a restart did not fix it, but restarting between uninstalling and then installing it seemed to do the trick.

bouquetcatcher: This did not work for me :(. I even uninstalled the game direction from the computer and did a fresh reinstall through Galaxy. I just played this game last night, but when the client updated it said 0 games installed. Installing them appears to work, but clicking play results in a black screen, then a smaller black window, then smaller, then nothing.

oncologist: Using GOG Galaxy 2.0.17 on Windows 10. My issue is simple: clicking "Play" on any GOG game results in...nothing. No error, no hung process, no new window. The game is not launched and nothing happens. The only way I can launch games is to manually open the install path and run the executable manually. I have tried running Galaxy as an administrator and still no luck. I have tried multiple games and this is absolutely not game-specific. What's the deal?

I should add that cloud save sync is not working as well: "Cloud sync failed" for all games.