@rikzombie, this kind of desyc happens when
//data is not cleaned after you have created the map. What both players should check before starting a map is go in /data and delete the following files and folders (if exist):
- index.bin
- RMGTemp
You can check this guide. All known issues and preventions are described there.
Thank you @Uraabk! I am gearing up for release!