By the looks of your video it seems your game was hit with a terrain rewrite bug. Or md5 error as it's more commonly known. This is an issue the team is aware of and working towards fixing. If you have not seen, we have a thread dedicated to md5s and some potential unofficial workarounds that can be found here https://7daystodie.com/forums/showthread.php?50175-Known-Issue-Terrain-Rewriting-(MD5-Issue)