The servers which try to check your minecraft session ID are down for maintenance. this is not a bug. But if you still can't rejoin even though the servers are online (You can check this account https://twitter.com/MojangStatus?ref_src=twsrc%5Egoogle%7Ctwcamp%5Eserp%7Ctwgr%5Eauthor ) Then I won't be able to help
You haven't specified the summary and how to reproduce it. This isn't a bug report
Alex reports things
The servers which try to check your minecraft session ID are down for maintenance. this is not a bug. But if you still can't rejoin even though the servers are online (You can check this account https://twitter.com/MojangStatus?ref_src=twsrc%5Egoogle%7Ctwcamp%5Eserp%7Ctwgr%5Eauthor ) Then I won't be able to help