After playing without any issues for a few hours, the Play button on the GOG game screen is now grayed out. It's the only one of my games that is doing this, so I wondered if it was a problem with Schizm. Anybody been having this problem or know a fix?

I know this is an old topic, but I had this issue too.
I was using GoG Galaxy 2.0 beta. And Schizm's play button was greyed out. I restarted GoG Galaxy and it was back to normal. But my play time counter is now at 80 hours while I actually played only maybe 5 hours. So it seems GoG Galaxy thought Schizm is still running and therefore didn't allow to start it again, and counted the time as play time.

Apparently the exe was runing i the background and needs to be closed manually. When it is done the "play" button use to be enabled again. Not need to restart Galaxy, It uses to occur ocasionally in old games under Windows 10. I can be caused by defender or the firewall, UAC, a different antivirus or any of the mess windows use to do with account privileges.

This solution is still relevant. Cyberpunk 2077 stopped "stopping" and the Play button is always grayed out. Looking deeper into the active processes (a ways down for me) I found it was a very small process idle but still running.

Now to find out what changed and why that keeps happening...