Alright, try and debug this puppy.
You open it, check out the error log -- nothing. Great!
Only, that's where the problem begins.
Save it as a MAP and try opening it. OH SHI- Hammer removes the brush because it thinks it is invalid.
Go back to the RMF and play around with the brush. Kudos to anyone that comes up with the solution. (This is an awesome puzzle, try figure it out!)
Goal: Get it working in a MAP format.
You may use vertex manipulation mode and the cutting tool. If necessary, you may create brushes. Remember that with vertex manipulation mode, if you select two vertexes, you can split that face or create a "line" between these two vertexes by pressing the CTRL+F hotkey (also, you might even be able to move selected vertexes around in the Camera O_o).
Good luck!
PS. This is a perfect single-brush example of how retarded and buggy Hammer is
ATTACHMENT: http://www.svencoop.com/forums/attachment.php?attachmentid=14217&d=1276815305
ORIGINAL THREAD: http://www.svencoop.com/forums/showthread.php?p=451301#1
Also, here's our OOT Total Conversion project: http://www.svencoop.com/forums/showthread.php?t=38028