Trying to bake from multiresolution modifier freezes Blender

Hi guys. This is my first time trying to model an organic mesh, mostly as a learning experience, and im in the process of (trying) to bake the normal details to the low poly mesh. Ive done a few simple tutorials about this and im pretty sure im not missing anything, but everytime i try to bake, it get stuck at 0% and apparently after a while, Blender freezes. It doesnt matter what i try, i tried changing gpu render to cpu, tried to apply all the modifiers, tried to bake to an even lower resolution model (just in case was something related to my limited graphics card memory), i cant find the issue. Also, i dont think it has to do with the model itself, i checked for doubles, bad geometry and other things. Maybe i forgot something, i could not tell.

Anyways, this is the blend file. Im trying to bake from the multiresolution model on level 4 viewport, to a multiresolution model with level 1. From the mesh named “highpoly” to “highpolylowdetail”. Any help would be really appreaciated. Its true that i will probably end texturing it on substance painter, so i wont probably need the baked normals and such, but still, i just need to know why this is happening so it wont happen again in the future.

Thanks in advance. Note that the blend file is about 99 mb. I needed to upload it to dropbox instead.

Nobody has a clue?