Thank you for the quick reply and quick fix, Rucksacksepp! I can confirm that they keys are working again.
And thanks for the tip about siege.exe and GoG Galaxy. I'm an old school player, i don't care much about achievements, but it's nice to know they work with GoG though Galaxy.
As a side note, as long time player of Infinity Engine games and NWN (i was there playing it's modules when the old Vault was a thing), i don't know how could i have missed this game. I'm still in the beginning (cp1) but i am already enjoying it a lot. The writing is amazing and leagues away of most modern (or even older) RPG's. It's a pity that it was not as successful as it should.