Family-Sharing gives you the possibility to use your games you've bought on multiple accounts SEPERATLY.
Since you bought the game only once you are sharing the same KEY.

I'm suspecting that you're trying to share CS:GO? If that's the case, CS:GO will have restrictions when shared to another account. The multiplayer aspect of the game is fully disabled, the user are only able to play single player aspect of the game.

This is to prevent people from creating smurfs and leveling it up to get ♥♥♥♥♥♥♥♥♥♥ so they can sell it for real money.

Also, only one person can access a library at a time, if your brother starts a game from your library, you won't be able to launch anything in your entire library until he leaves it alone.

So for carlonnye say that cs go it is limited by multyplayer point of view ? brush so you can buy another acc -on in the game? anyway in my computer used two ACC ..thanks the fast comment!:)

When trying to accept an invite to game share from my other account, it's telling me that i'm not logged in as that user that rec'd the invite....but I am. I've logged in & out as directed in one of these forums, but nothing is working. I get the invite from my other account, I just can't accept it. Anyone have a solution?