I changed the file name - I did not make a copy.

Just to make sure we are on the same page, you are getting the message as you are trying to get ready for e-filing, it isn't a rejection notice that a return has already been filed with that SSN?

Doesn't say a return has already been filed with that SSN it says another file with the same SSN is marked for e-file.

Single or joint return?

On the original file that you renamed, remove the X from the E-file box for Federal and State on the Information worksheet, open and close the State, close the file. Click on the Fix Duplicate SSN on the file in the EF center and that should fix it.

Where do I find Fix Duplicate SSN?

This may be helpful if you're seeing "Fix Duplicate SSN" https://accountants-community.intuit.com/articles/1606794-how-to-correct-return-duplicate-ssn-ein-wh...

Thank you!!