When trying to E-file a Minneasota return I am getting the following message. 

"Credit Tax Paid to another State requires the other State Tax Return to be attached as a PDF for electronic filling. A PDF may be attached by going to the E-file tab in the menu and selecting the attached PDF files option" 

I have already attached other State Tax Return and the error message is still there. Can someone advise if you have seen this error message before.

Thank you.