Well from an initial look, it seems the mdl/mdx header doesn't match the contents of the file.
Header:
Model "HeroMountainKing" {
NumGeosets 8, <-- you only have 5 in file
NumGeosetAnims 5, <-- You have none in file
Also the texture count and such is off. The viewer doesn't care but WE will throw the flag! I've tried modifying this but it still crashes. All I can say is the file looks pretty crowded. Lots of playin around with emitters and added animations. If you have a backup of the geomerged model I'd start there testing if the model works then add each stage, animation transfer, emitter work, and so on. Hope this helped,
Cheers