The IRS apparently has information in its database that suggests you or someone on your return received an IP PIN or a particular notice.
What's relevant to you isn't necessarily why the IRS has that information but, more importantly, the fact that you won't be able to electronically file your return while that information is in its database.
You can contact the IRS to see if your account can be updated to get past this, but it's extremely unlikely. For telephone assistance, see Telephone and Local Assistance at the IRS' Let Us Help You page.
If the IRS can't help you, there's nothing you can do to fix your return and e-file it. You'll need to file a paper return instead.
Please see the TurboTax Help article Why can't I e-file my return? for more information, and How do I print and mail my return in TurboTax Online? for printing and mailing guidance.
See also the article E-file reject IND-996.