Can I update a Make Human model in Blender without losing my animation? I did a lot of animation on an mhx model in Blender before I realised she had holes around her neck. Someone on the Make Human forum suggested I use an mhx2 character which solved the problem. Is there a way I can just update the character from within the same Blender file without loosing the animation?

I tried exporting the animation as a bvh file and reloading it onto the mhx2 character in a new Blender project but I've had all sorts of problems. It imports a skeleton of bones which walks downward on its own, or a tiny one which walks sideways on its own or some upside down orange balls which wander about. It's obviously got the animation which is good, I just can't get it to attach to the mhx2 character.

So to be clear I either need to


just update the model from mhx to mhx2 within the same project and not loose the animation
Export the animation as a bvh file and upload it onto an mhx2 character in a new project
Work out why my mhx character was making holes  around the neck in the first place and fix that. (this is the option I prefer as I need the project finished tomoro but i would like to learn all three)
I'd go with option 3, especially if your deadline is tomorrow.  Especially if it's just a matter of re-topoligizing, and then re-weightpainting just a bit.

If you want to learn from this, I suggest try having a master-slave style rig.  That means you have one set of bones you animate directly, and those bones in turn constrain a bunch of 'slave' bones that only deform the mesh.  That way if you want to re-import your model later on, you can simply re-constrain those 'fresh' new bones to your older animation rig.  

You can even have two separate armatures, one for deforming, one for animating to make the re-constraining process clear to yourself.  Although I've found this method a tad obscure, and not considered canonical Blender rigging.