neo2fe: well happened to me today too, installed gog galaxy, dowloaded game but after click play it appear gray and after synced cloud it appear back green and nothing happen, all C++ installed, direct x too. last graphics drivers too. Game simply no react... What to do?
The GOG Galaxy defeats the point of DRM free.
Remove what you have installed.
Go into your account, by clicking on your name and then Games.
Click the icon for Witcher 3 and download all of the Witcher 3 files into a folder.
There are 10 of these. One is the installer, the rest are bin files. It should look like the enclosed image files_image)01.jpg
Now double click the file called:
setup_witcher3_en_goty_2.0.0.51.exe It takes a while to install. You must have a legal copy of Windows. You must have the Windows updates.