Two things: as of sometime on Saturday (9 March) it was possible to go through the original check and get to a point -- where you could file *by mail* (e-filing is still blocked). [Well, now that I think of it, that might get blocked further down the path...we didn't try to complete things that way...]
We then went back and finally found that somehow we'd gotten a blank "person" on the forms for the 1095A (sorry, forget the exact details as my wife made the discovery and correction). Eliminating that, and the form went through and we were able to e-file. Not sure if this is the only thing that triggers that specific error, but correcting it (which, of course, made no difference in the tax calculations) solved the problem for us.
