Import EFT File Format not working

I have a Test company that is a copy of the Live company.

I set up an EFT File format for US - NACHA IAT in the live company and exported it to a file.  I logged into the Test company and tried to import that file but I keep getting the error that the Import file is missing or not valid. Please select a valid import file.

 I have tried as txt, csv, xlsx and no file extension.  Nothing works.