Disconnection bug

Recently I have been losing connection while making custom maps. This only happens with custom maps and never happens any other time. It may have been the size of the maps I was working with, but it has always worked up until now.

Please help, I can't even start my South America map because of this.

I have heard other players complain about the same issue.

Please try to reproduce the steps necessary to get yourself disconnected if possible, so devs are able to look into this.