Internal Exception: Java.io.IOExeption: An existing connection was forcibly closed by the remote host.

This was a message when I logged into a Realms server my friend owns. For 15s the pressure plate responded but didn't open the door, other things didn't respond before an old error of "Internal Exception: Java.io.IOExeption: An existing connection was forcibly closed by the remote host" popped up. Luckily, after 10m the Connection was normal again.