Root element is missing when testing EDI map

Great thanks to seanishere for providing the insight into what is happening
in the Biztalk EDI and AS2 forum, I thought I was losing my mind. Since this
has been an issue for at least 2 years now, does anyone know when this will
be fixed?

quoted from seanishere:
"This is definitely a bug. If both the source and destination schemas for
your map that you are testing reside in the same project you are testing then
the "test map" function will work fine, however, it will fail with the error
"root elemet is missing" on the inputfile.xml if the source schema is an
external reference. You can try copying your source schema into yoru project
for testing and remove it before you are deploying the project."

Actually, I think it's only an issue with the Source schema. My map from
X12 4010 850 to internal Flat File works fine with the destination schema
referenced, so long as the X12 source schema is included in the project