I've made an extremely small, simple map to try and wrap my head around zoning (i'm new) and I get the fx 400 error for the map.
http://imgur.com/AadAFtA
Please help.

when you first create a mod, it loads all the Der Reise stuff - which most of the time you dont need

go to root/zone_source

find dlc3.csv

open it, and comment out unneeded fx ( put a "// " before each one )

you can also do this to :

mymapname.csv
mymapname_patch.csv
nazi_zombie_factory.csv
nazi_zombie_factory_patch.csv
common

i forget which ones exactly but i believe "6" of them are loaded into your mod

when thats done, recompile your map, rebuild mod

thanks so much

no problem, glad i could help