Sorry to jump in, but i'm having the same problem as Layton322.Since I'm the guy who implemented that part of the code, I could definitely help (probably).
1) What was the specific error?
2) At the moment, the code explicitly ignores anything that isn't custom music (because the number of mods that does anything involving custom unit sounds or soundscapes approaches zero). Since it doesn't crash for anyone else, I can only guess you might have a unicorn-a mod that actually tries to do something unusual with the sound system.
I turned off anti-virus, so everything else went super fast, even the Lang_EN_US went right though. But then when it came to "Audio_SoundScapes" and says "Did you crash here?" it stops. I waited about 15 minutes for it to continue, but it didn't move.
I thought it was one of the mods, so I started removing them a few at a time and tried the mod again. No luck. Again and again it stopped at Audio_SoundScapes and "Did you crash here?" It's not one of the mods. I removed every single one, so that all that was left in the mod menu was Multiplayer ModsPack Maker (v.1) and I still had the same problem.
So yeah, I have no idea what's causing it.
If I can figure it out I'll post again, but I too am bemused