When I enter my street address, I get an error message telling me I "need to provide a street address, not a PO Box." But I AM providing a street address. Help!

I'm all finished entering information and am trying to file. I'm at the page that says "Thanks! Now confirm your personal information." When I enter my street address, I get an error message telling me I "need to provide a street address, not a PO Box." But I AM providing a street address. It is definitely NOT a PO Box. Help!