What he means is, did you install the game from GG on this same PC? Or copy it there from another PC? If the latter you will have to run the GG installer and formally install the game on this PC too.
If that's not the case, Try a full clean reinstall: Move valued save games elsewhere, and uninstall the game. Manually delete the CK2 directories from where GG put them and from MyDocuments. Reinstall the game (this time pick somewhere NOT under the system path c:\program files\ ), download 1.111 patch again and apply it