i've a problem with a game.
i'm stuck in a quest, when i finish it should be the movie starts to load but nothing happens.
I tried everything , I uninstalled gog but not worked, I wanted to try the rollback function but does not authorize me he said: The witcher 3 installation fail. why?? any advice?
sorry for my English, i'm using a translator.
Thank u

Could you be more specific? The text you posted seems to describe a technical problem with a game you're playing, but you don't say which game is, where are you in your game, and what exactly are you doing that triggers your problem. But your screenshot shows something totally different, and it shows you're trying to install The Witcher 3, but somehow you're not allowed (revoked?) and that's why you can't install it, probably because you bought/got it from a different place than the GOG store, and that place was not licensed to sell it.

You should try to contact GOG Support directly here if you bought your game from this place: http://www.gog.com/support

If you got it from somewhere else, contact the source instead.

Also, if you have a problem with an specific game, go directly to its forum instead of using the general forum. That way you will get better answers/information about them. Type the game's name in the search bar found here: http://www.gog.com/forum

what i see in your attached pic that it shows that you don't seem to be connected which explains your issue with rollback or reinstalling
to get connected click the "connect now" button

note: you need to be logged in to the account that the game is owned on to play it on GOG Galaxy

you may have missed something in the quest that triggers the movie but without more specific information on the quest you were stuck on no one can really help you