Order Import 'Cannot fetch a row...'

Once every three years or so, I have to do an order import, mostly from one facility to another within our own consortia's database (our sub-licensee's like to do co-productions).  And every time, I waste at least a day fiddling with the import xml file and troubleshooting esoteric errors.  Today is no different, and I'm hoping someone has seen this before and can help.  We would really like to use the importing barcode feature and it's time to print tickets!

First, the problem is not with SQL Server being unable to read the file.  About 3 hours ago, I got a test file to import just fine.  And the xml format file and the data txt file are sitting smack dab on the C: drive of the SQL Server.

I have tried the standard format xml file as delivered with the 12.5.1 installation files.

I have tried commenting out specific elements of the above xml file.

I have tried deleting specific elements of the above file.

I have had 2 other colleagues proof the txt file and compare it to the above xml files.

I have restarted SQL Server (of course, I'm doing this in TEST).

I have not tried opening a bottle of wine.  Yet.

Here is the error message:

"Error getting data from C:\Order_Import\DTH_Test2.txt5 - Cannot fetch a row from OLE DB provider "BULK" for linked server "(null)". The import file data may be out of sync with the specified format file.

There is also an error message above it,saying that "the file OrderImportStandardFormat.xml does not have a valid extension (xml) and will be skipped."  I would have normally thought this was a smoking gun, except I did get a wee test import to go about 3 hours ago.  Plus I see other people on this forum have gotten that error, and also had successful imports. 

Thanks!