I had honestly forgot about it with all the stuff I've been doing...
It definitely crashed the game on my end too, so I opened it up in ERFEdit, extracted all of the files to a new folder, and closed ERFEdit.
I then re-opened ERFEdit, went to the File menu, selected "New", and made an "end_m01aa.mod" file with the extension dropdown thingy set to .mod as well. After that, I just dragged all the files back in, completely un-modified, saved, and loaded up the level in-game.
Everything worked fine.
Given that, I think you skipped some steps from my detailed walkthrough somewhere. The .rim and .mod files have different data in them, so ERFEdit needs to be re-opened (thus, "reset") when switching between the file format it's working with.
https://www.mediafire.com/?ktsov4gz7ebkufs