Message Severity: 3
C:\Battlefront2\main\Battlefront2\Source\LuaHelper.cpp(312)
CallProc failed: bad argument #1 to `SetAmbientMusic' (number expected, got nil)
stack traceback:
[C]: in function `SetAmbientMusic'
(none): in function `ScriptInit'

How could I fix this?

Somewhere in your LUA you have something like this:
SetAmbientMusic
and you should comment it out to fix it
--SetAmbientMusic

Also, doing this should fix the map but the music might not work. The actual problem is that you're using a bad setting or calling a non-existent music stream or something to be ambient music.

Since it says "Number expected, got nil[blank; nothing]" I guess its probably SetAmbientMusic(1) FOR ON and SetAmbientMusic(0) for off.

Okay, thanks. I got it fixed now.