Add a specular map.
Make the spec map darker if it looks wet ingame.
Check "berlin_wood_beam" xmodel spec map for an example of darkness.

If you didn't fix your lighting/shadows upload the .map and i will check it.

In a new script placer map the shadows work so you must have deleted/changed your skybox or lightgrid or worldspawn settings.

Make backup of your mods/mapname/
Merge clientscripts/ folder with your mods/mapname/
Check file in launcher/mod builder.
It should get rid of the footstep error.

https://www.mediafire.com/download/ttdu1lwzouachiz

Are you using ugxmod?
Did your map compile before?

gympie is probably correct and your calling a custom script with a flag_wait in it before the flag is defined. Moving it under zombiemode or load would ensure that the flag was defined.