Okay, problem partly solved... I'm accessing the files off of my old CD-ROM Red Alert game, rather then the installed First Decade version. (Loading main.mix is the cause of the start-up crash as well unless you hold shift.)

However, and this is a major source of confusion for me, I can't seem to find the file "map.aud" anyway on the Allied or Sovient Disk. It's the map music theme (duh). I've tried every mix file I could find on the disks.