Earlier while working on your tax return, you were prompted to 'attach' a PDF to your return as required for your tax return. Attaching 'registers' the file location with TurboTax so that later, when efiling, it can retrieve the document and send along with the tax file. The error you are seeing is usually due to TurboTax not being able to locate the previously selected file. Be sure not to move, rename or delete the file so that it is available to the program when you efile.
