When I tried to reset a world on my realm it came up with "null-0."  However, it did indeed reset the world. 

This was very confusing, and I still do not know if this will cause issues on the realm, or if I should try and reset it again.

The realm kicks my friend and I every 5 minutes, with an error code appearing or "Server Closed."  It also deletes the progress we made in the past 5 minutes.  However, it seems that these issues do not go hand-in-hand, as many others have experienced the server closing/deleting progress issue.