Well, my previous message was obviously not meant to cause you really having some troubles with the install. This leaves me with the unenviable task of troubleshooting a case where the one in trouble is a TWC legend.
First, you are trying to install MOS 1.7, aren't you?
Is your MTW2 a Steam version or the good old disk version?
I have no idea why the export_descr_unit.txt would be a problem. Obviously this is not something that is happening often. In fact I can't remember seeing it before. I attached a copy of the file from my own install to this post. You can replace the existing one with it and see if that solves it. Also I wonder if there may be some problems with the MOS file and folder properties.
Recently lionheartx10 made an install video for TATW, MOS and DAC. It's pretty decent and perhaps you will spot something that may help you.
LINK