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.

It shouldn't be happening on a new script placer map.
//
That error comes from using a command like
flag_wait "all_players_connected" before
flag_init "all_players_connected"
If you have developer 1, developer_script 1, and logfile it should tell you the exact file and line the flag is called from.

Map_source contains prefabs and maps.
Mods/mapname/ contains custom scripts sounds ect.
Zone_source contains csv associated with your mapname.
Custom models and textures will need the gdt and original files associated with them.
//
Create a new map with a script placer on your new computer. Compile and test it to be sure you installed modtools and updates correctly.
Replace your NEWmapname.map with your OLDmapname.map
Copy any csv edits into your new map csv.
Copy any custom scripts over and update your mapname.gsc

Use a script placer to create a new map.
Check ugx wiki for instructions.
Don't use "test" or "example" as a mapname.

If your using ugxmod then you need to add all the ugxmod perks, elemental machine ect.

Look in the console when it freezes for anything important.
Check your mapname.gsc and see if you added anything twice by mistake.
If it happens when you get items and when the game starts maybe your player quotes are not setup correctly.

Radiant toolbar "show patches as wireframe"
There is also "j" , "shift + j" , "ctrl + j" to toggle the red highlight and textured wireframe modes when blending or vertex editing.

You don't need bsp_info checked when compiling.

Is there a mod menu installed?
Are you using T4m?
Are there any loose files not in a folder in your appdata/codwaw/mods folder where installed maps go?
Does the campaign or stock zombie maps load?

You could have a bad kvp on your worldspawn. Open your .map in notepad and compare the first few lines to another working map to see if you deleted something.