Solution:
During the e-file process, TurboTax is supposed to auto generate this pdf, save it, and attach it. For some reason, this doesn't always happen. For me, it was the federal that glitched while my state was just fine.
Take note of the file location that turbotax is looking for the missing file.
Save the return you wish to file in PDF format in the folder that turbotax is looking for the attachment.
Change the file name of the saved file to the exact file name that turbotax is looking for.
Once you have the exact match, transmit the e-file, and you should be good.
Note, if your problem is with a state return, make sure you save only the state portion of the turbotax return and not the entire federal+state. If you save the whole federal+state file and go through the steps, it will still bypass the error and get the return filed, but your state comptroller might not look past the federal portion of your returns before seeing your state returns.
