World of Warcraft animations too big for Source?

I’ve been trying to port an animated World of Warcraft NPC (The Fel Reaver, to be specific) for a friend, but when I run it through StudioMDL, it gives me an EXCEPTION ACCESS VIOLATION (assert 1) error.
After trying again with a significantly shorter animation (About 1000-1400 frames), the model seemed to compile just fine.
Does Source have an upper limit for keyframes per animation?
Is there a way to bypass this limit?

Or to compress animations in 3DSMax?

For anyone that runs into this issue, try using GUIStudioMDL. Worked for me.