As stated in the sticky at the top of General Support,
"Unfortunately, this is a server-side glitch that can happen from time to time. Whenever this occurs, you have to wait until the next server reboot to play again.We have daily reboot also. Sorry for the inconvenience.
In the rare case, this issues cause by your low connection when you play game and got disconnect, and can potential solved by close completely client and open again. If not solved, you will need wait to reboot."
Ok, thanks