Importing from Access: Expression Error "column foo.value of table not found"

Hi everyone: 

I am new to PowerBI (and BI in general). For a work project I created a *very* simple Access database (~40 records, 15 columns, a few columns link to simple tables like "Country." I tried to import to PowerBI so I could put the data on a calendar and look at it dynamically. But the Access data won't import, it says:

I cannot figure out what I need to do to make it import. It looks like the addition of ANY table to the main table will trigger this error (I tried making a completely flat, one-table DB and it worked. But then I couldn't get the dynamic views I wanted).

I've seen other errors similar to mine resolved, but the fixes don't seem to apply. Any thoughts?

Your help would be GREATLY appreciated!!

Best regards,

David