says it failed to load game database

Check this:
https://www.gog.com/forum/general/gog_galaxy_update_proteus_brings_customization_options_gog_wishlist_and_more_e360f/post45

Those who don't mind dabbling with an SQLIte editor, see [url=]https://www.gog.com/forum/general_beta_gog_galaxy_2.0/the_failed_to_load_game_database_error/post101]Skolia's solution[/url].

They have fixed the problem !
Just download the newest Galaxy client from the link on the bottom right at the front-page , then install that.
That should fix the problem. at least it did so for me. I had *NOT* started messing with the installation myself and had not attempted any of the fix suggested as I did not want to risk screwing up anything.

Thank you to everyone in forum for their fix for the problem or for trying to fix it , Thank you all !!!!

Also thank you to GOG for a speedy fix of their huge screw-up !

Official GOG post here :
https://www.gog.com/forum/general_beta_gog_galaxy_2.0/the_failed_to_load_game_database_error/post134
and
https://www.gog.com/forum/general_beta_gog_galaxy_2.0/the_failed_to_load_game_database_error/post137