This happens to me sometimes when I Click on a server and disconnect really quick. I recommend exiting out of Minecraft and then opening it up again and trying to join again. If that doesn't work, restart you computer. Hope I helped
Silly question probably but you're not playing with any mods are you? Sometimes mods can interfere with connections. If not then change your password. It may be that someone else is playing with your account on a different server at the same time.
Same problem. Used to be able to play in the browser on multiplayer before the last update.
The response from Mojang:
I don't believe that anything has changed with the game. The browser version and the downloaded version are the same game, and are completely interchangeable, but some users report more success with the downloaded game, often due to issues with their web browser; an issue that the downloaded game does not have.
But this doesn't explain why I have been able to play multiplayer in the browser version since we joined in January and now all of a sudden it doesn't work. Able to login okay, Router was pinged, port was checked to be open,and the port forwarding still works with my Skype program - so why won't it work now?
Paid for both accounts, restarted, changed password, tried with both of my accounts, contacted Mojang - nothing working.