"Error during core initialization sequence" message keeps poping since yesterday when i try to launch GOG galaxy 2.0. At some point the troubleshooter managed to fix the issue and indicated that it fixed the incompatibility of the programm. But today same problem reoccured. Any ideas what the problem is?

Sorry, your nuclear plant is broken.

is there any solution to this?

Buy a new one. :P

Btw, I see that you edited the OP.
For Gog Galaxy maybe you could reinstall it or contact support.

Your computer is about to do this

Yeah i should have clavirified that from the beginning (i have contacted the support btw i just wanted to check for anything else till they answer) and because the stores are closed because of the quarantine i thought that i would be good to exclude every other possible option first. Anyway, yesterday it worked fine for about 5-6 hours and it happened again after i shut it down and turned it back on today.
Whatever, i really apreciate your help mate! Thank you very much

Uninstall galaxy, then play your game from the installed exes, or desktop icon if installed from offline installers. Galaxy is optional.

UPDATE, just for anyone that might have the same problem and because you guys are very helpful (not implying that you all care about the outcome of my extremely technologically illiterate problems) :)
The problem seems to be with the coordination of the galaxy with the windows, because the default option was windows 8 and i run 10, so in the troubleshooter when it asks if the programm used to run properly on a previous version of windows, i clicked yes and the when it asked on which software it used to run properly the correct answer seems to be
"i don't know" ( the other options are windows 8,7,vista etc but not 10). So by clicking "i don't know" it probably tries every possible combination of cooperation and then it functions. PROBABLY
Thanks again anyway guys.

Weird.. the troubleshooter doesn't seem very clear then.
Btw you can select\check the compatibility options directly in the file's properties (or at least, it was possible in Win7).

Happens to me from time to time so I will write this here to have the answer next time it happens and r/gog on reddit goes dark again.

SOLUTION

Go to C:\Users\<username>\AppData\Local and delete GOG.com directory.