After a player rides a horse in realms the realms crashes and no longer lets people on to it

After my friend rode a horse it crashed our realm. We could not connect to it for a few hours. My friend was unable to get on later on, but I am not. I keep getting "this may take a few moments" and then "disconnected from the server"

I have tried everything from restarting MCPE, my wifi, and then uninstalling and reinstalling.

But I have no luck getting back on to the realm