kittles

I am very new to this so please excuse my basic level knowledge. I can run the minecraft launcher and add a server and everything seems to be fine. But everytime i try to connect to a server i get the "failed to connect to server. Failed to login: invalid session (try restarting your game and the launcher)." I appreciate any help possible as i read previous posts and they are all too old to be relevant to me. *NOTE: I am running it on windows 10 could this be the problem?