Hi Everyone!
The exe patch file worked for me.
I followed the instructions and ran the exe file while the Liberkey was running /in english (UK) regional setting/. It patched some files. Then I changed the xp back to my default Hungarian regional settings and the Liberkey started working here, too.
I tested a couple of applications and they all work fine. No "Fichier de Configuration invalide" error message any more.
The application update also got healed and works well, I just updated todays applications without any issues.
I have not found any problems yet, well done, dear developers!
Best regards
kmatalik