Family Sharing

[TheGuru]

I have downloaded this game off my brother onto my computer and it has the option to play - the button says play - but when I start it uplay has an error stating some authentication issue.

Would steam really allow me to download a shared game and then let another piece of software tell me that this game cant be shared?

or am I doing something wrong?

[Neodrauka]

Can all Steam games be shared with friends and family?

No, due to technical limitations, some Steam games may be unavailable for sharing. For example, titles that require an additional third-party key, account, or subscription in order to play cannot be shared between accounts.