When I click "Play" in GOG-Galaxy i get to the options of B17. Tried different settings. If I click "Play B17" the window closes and the button "Play" in GOG-Galaxy gets green again. Also on low-settings.

Can anyone help ?

Firstly, try running it outside of Galaxy. Either from the shortcut created by the installer on your Desktop, or go to the game's installation folder and run "B17Setup.exe" from there. When in the options, set the graphics resolution to as high as possible within the limits of your monitor. Also, make sure you go to the Options tab and click on "Create Graphics Cache". By the way, what is your current installation folder for the game?

If the above doesn't make any difference, then uninstall the game. Reinstall it, but using the standalone game installer and NOT via Galaxy. Accept the default install location. Repeat the options setup as mentioned above.

Also, make sure you have the very latest graphics drivers installed for your video card.

Let me know how you get on.