A fan on the Call of Duty: Black Ops Cold War subreddit has found a way to work around the texture glitch affecting players on the Xbox Series X when they try to play the new Zombies map, Mauer Der Toten.
The glitch in question causes the walls and some floors of Mauer Der Toten to fail to load their textures, making the map all but unplayable. Reports of the bug have so far been contained to players on the Xbox Series X Enhanced version of Call of Duty: Black Ops Cold War, but the bug is particularly frustrating as the map is brand new, and players want to explore it as quickly as possible now that it's available.
The first workaround requires that you have an external hard drive, onto which you can download the un-enhanced version of the game. Because the bug appears to only affect the enhanced version, you should dodge it entirely.
The second option darkrangeresp suggests is letting the game sit on the menu for the Zombies mode for about 40 minutes. They say this waiting time gave the game a chance to load all the textures, and that doing it resulted in three successive correct load-ins of the map.
A comment on the post also suggests deleting the HD textures, although that commenter and others noted that the train on the map can still cause frame rate problems or crashes without HD textures.