As reported by @sara-mokhtari: on the installer, only truncated_octahedron (the C + Python model) is working. The three pure Python models (tetrahedron, truncated_tetrahedron, truncated_octahedron) all fail with the same error as before:

NotImplementedError("Magnetism not implemented for pure python models") 
NotImplementedError: Magnetism not implemented for pure python models (it is not possible to perform a fitting at all)