DO NOT include "/tag/Beta" in the URL. This only shows the two year old 1.0.4 Beta version, which is broken.

The proper URL to find the newest versions is:
github.com/ABaumher/galaxy-integration-steam/releases

I can confirm that 1.2.1 currently works.

I've had this problem and solved it about a year maybe year and a half ago with the oft mentioned fix from github.
Many thanks to the guys making it.

But today the problem resurfaced in an odd way.

Steam plugin is registered as offline, retry button does not seem to do anything.

Several restarts of GG, Steam and PC, also including a new download and "install" of the fix in case something had gone wrong, same problem.

No steam game can be launched, play button is grey and Steam registered as offline.

However if I start a particular game through steam, I can later start that same game through Gog Galaxy, Play button again in happy colour mode.

Anyone has an Idea of what is going on ?

Yes works fine with this 1.2.1 beta version...Go with it

Worked for me too, Windows 11 24H2, January 16th 2025.