My friend and I have this issue, I've found that my friend has no problem joining and playing on my server until I join, then once I join his game has that error and can not rejoin even if I leave the game he justs get stuck at downloading terrain. The error has something to do with the world file because if I delete the world folder he can join again but gets the error again once I join. I hope this helps and I'll do more research and try to find the file that causes it.
Update: It doesn't matter if he runs the server or if I run the server the error happens. (To me if it's his server and to him, if it's my server.)
Joe Conway
My friend and I have this issue, I've found that my friend has no problem joining and playing on my server until I join, then once I join his game has that error and can not rejoin even if I leave the game he justs get stuck at downloading terrain. The error has something to do with the world file because if I delete the world folder he can join again but gets the error again once I join. I hope this helps and I'll do more research and try to find the file that causes it.
Update: It doesn't matter if he runs the server or if I run the server the error happens. (To me if it's his server and to him, if it's my server.)