stop on unrecognized qresult in rpz_rewrite()

[Lee]

I tried to go to https://fpki.idmanagement.gov/ and got some error
message about not finding the site with a "try again" button.  Tried
again and it worked:

29-Sep-2018 15:56:21.677 queries: info: client @000001F0C8672910
127.0.0.1#58997 (fpki.idmanagement.gov): query: fpki.idmanagement.gov
IN A + (127.0.0.1)
29-Sep-2018 15:56:21.708 query-errors: debug 1: client
@000001F0C8672910 127.0.0.1#58997 (fpki.idmanagement.gov): rpz QNAME
rewrite dfew6wnpm1gb5.cloudfront.net via dfew6wnpm1gb5.cloudfront.net
stop on unrecognized qresult in rpz_rewrite()failed:  : SERVFAIL
29-Sep-2018 15:56:21.708 query-errors: info: client @000001F0C8672910
127.0.0.1#58997 (fpki.idmanagement.gov): query failed (SERVFAIL) for
fpki.idmanagement.gov/IN/A at ..\query.c:8580

29-Sep-2018 15:56:34.893 queries: info: client @000001F0C91812E0
127.0.0.1#51991 (fpki.idmanagement.gov): query: fpki.idmanagement.gov
IN A + (127.0.0.1)


I tried searching on the error message & got lots of pointers to
query.c but I haven't found anything that explains what happened.

I've got nothing for .net or .cloudfront.net in my rpz.zone file & the
rpz zone is configured as
   response-policy { zone "rpz.zone"  log yes; } break-dnssec yes
recursive-only no  qname-wait-recurse no;

Can someone tell me what can cause
  stop on unrecognized qresult in rpz_rewrite()failed:
or how to fix whatever it was?

Thanks
Lee