clarry: Ah, actually the problem my sister had was that all the options there are grayed out. So you can't actually do anything. And galaxy says installation fails with configuration error, when all the files are already there and the game is playable..
Is she the owner of the game? This may be the issue. If the game is somebody else's have that person log in to the client and the options should become available. Then you can upgrade / downgrade the game to your convinience
sniperkiwi: Guys, manage to by pass this.
If you go to the game settings in the client, you can stop the game from auto-updating (sub menu: override features). Well, turns out that if you that then you get to choose the version and even downgrade. I'm adding screenshot for clarity.
Hope this helps!
Cheers!
Weware: That's a really nice find ... for those who can use the Galaxy Client at least :)
Thanks! Took me a while to find, so I thought I'd share the info.