@nprofile1q... Yeah, it's a frustrating error, and that's all it's telling me. It generates fine with Batch in Robofont and I can open it in Glyphs. Only fontmake is stumbling.
Regarding the discussion about getting away from Monotype: Remember, Proxima Nova is used by giant organizations all over the place and it was sold by a one-person shop.
You don't need to buy type from a large organization just because you represent a large organization.