@Jim-from-Ohio  FinCEN's PDF files are not the most user friendly because of their limitations of special characters.

Did you use the File Online BOIR option, which uses an online form that should be the more streamlined than a PDF?

If you used the File PDF BOIR option, did you hit the Validate button before uploading the PDF?  The validation will help you weed out all the illegal characters and correct various errors that could prevent the file from being accepted (at least for discretionary e-filing of FBAR).