Why has GOG Galaxy become so difficult to use - any games installed using it frequently crash and/or have large black areas in the game. Installing without using Galaxy is not much better. I have been collecting my favourite games on GOG for many years - 255 here as opposed to 95 through Steam.

I really do not want to have to move and/or buy my favourite games on another platform. I have been gaming since beta-testing pong last century and I thought that I had found the perfect place for all my gaming needs :(

Galaxy has outlived its usefulness and it's time for it to end.

I really don't see how a launcher can give you black areas in games or crash your game. Sounds more like you have some other issue with your PC

Issues spread across multiple programs does sound like a system issue. Have you tried doing a stress test on your system or sunning a diagnostic?

Last time I had issues across multiple programs it turned out my graphics card was starting to fail and I needed to replace it.

Here's an obvious test:
Try running the games without Galaxy - shut Galaxy off and run the games via their installation manually. If they continue to react the same way it's not likely Galaxy at play. More like a video driver update recently nuked something.

I've experienced something similar, except that it was white areas from textures that were failing to display. Like the other posters, I think that you have an issue with your computer's graphics card... or possibly its driver. If you are on an older laptop, the issue could be that the games in question is just pushing the computer a little too hard where you are lucky that the games in question are even running.

I would try reinstalling your graphics driver. If that doesn't rectify the issue, you may need to consider getting a new graphics card for your computer... or just a new computer entirely if this is a laptop.

Also Galaxy is just a waste of your system resources. Don't use it.

So by your own words, it's not a Galaxy issue.

It's very likely a graphics card issue. They can manifest in a variety of strange ways. From visual artefacts to straight up objects (usually flat planes) appearing in 3D games, blocking the view.

It may be time to look for a replacement.