This is not Intuit's Support helpdesk, no one here has access to the manual with all these codes. Clearly spell out the error message and someone may just be able to point you in the right direction.
Still an AllStar
Its an IRS rejection, not an error.
IRS Tax Return Rejection Code IND-517-01
Problem: The IRS - not eFile.com - rejected your Federal Income Tax Return because your dependent's SSN was already used on another Tax Return as a Primary Taxpayer or Spouse, and that return has been accepted. Only one return with the same SSN will be accepted.
So your dependent already filed a return and claimed themselves....maybe on the non filer site to get the stimulus money?