I've tried upgrading to
Substance Painter, version 2019.2.0
Build 3242 - 7c01df656b0c7602185fd275de419c6c6347bf49
Ran as administrator, import resource (no project open), once the material is in the dialogue it shows "an error occurred opening this resource, it cannot be imported" error again
[ ERR] <Resource Import> "F:/Substance/SubstanceShare/golden_moldy.spsm" cannot be imported as 'smartmaterial'.