Before converting mesh to voxels:

After:

(And I've tried it at a bunch of different resolutions but it always becomes deformed to some degree)
Next, I tried importing it as a QB file from Qubicle
Before attempting to convert the voxels to elements, it looks like this:

When I try the first method (1 element per voxel), I get this error

The second method makes the colors lose quality

And the last method makes it look like this for some reason

How can I simply get my models from Qubicle into minecraft models?