ok I found the problem. If you try to import and the first vendor is not in Mas90, it will create this error. If you add it then it will be fine. If a vendor is not Mas90 but further down in the import file, it will continue to import but just notify you some records were not imported. Is there a workaround so the first line of the file doesn't completely bomb out but still continues through the import process and just shows an error like it normally would.
