So I was working on my TARDIS on the server, but everything was laggy, my TARDIS display wasn't functioning even after exiting and entering, and I was the only one left. I thought maybe logging out of the server would fix it, but I got an "Invalid Session" Message when trying to re-enter. I followed the instructions saying "restart your game", but that same message cropped up again!

Is there some maintenance going on?  Is the server just messed up?

 You made sure to completely close out of MC and restart the game right? It usually fixes any invalid sessions for me