One more try at this. I found the issue that the .xml was not taking all the map points. v1.21

Huzzah! It appears to have worked. I started a map with heavy zombie count about a half dozen times and never did a zombie spawn in the null zones. And the map is appearing correctly.

Hopefully fixed the zombies spawning in null zones. Updated the map files and with any luck the buildings are showing up again. v1.2 released

Removed polygonal waterzone that may have been causing the vehicle spawn issues.
Removed the wall that should not have been in the camping department.
Removed a door for restroom upstairs that was added by mistake.
Added some more trash and grime to the map.
There should also be a light switch in the gun dept storage room.

My first try at a mod and the first version published.