I can't delete a K-1 that no longer exists.

[ToddL]

You may have a 'phantom' K-1 in your tax file.

Use the "Delete a Form" tool to remove the Schedule K-1 (and any associated worksheets).

See: How do I delete forms in TurboTax Online?

After deleting the Schedule K-1, log out of the program. When you log back in, use the Delete a Form tool to confirm the Schedule K-1 has been removed from the list of forms in your return. 

Also, if this 'phantom' K-1 does not have a "Partnership Name" entered, you may have give it one before you are able to delete the form. The K-1 interview is located in the Business Investment & Estate/Trust income section of Federal Taxes > Wages and Income.