Hi PJA5. It's a bit hard to give a specific answer with no knowledge of your tax situation or information on what the error is, but here are some thoughts:
First, the unspecified error that you reference might be a checkbox needing to be filled in on the form. You can try just deleting the form. Assuming you're using the desktop version, that's one of the boxes at the bottom of the form. If the form is actually needed, TurboTax will either not let you delete it, or it will just automatically come back again with the same situation.
Second, while you say that you don't "do" estimated taxes, respectfully, that does mean that they are not due in some circumstances. To oversimplify a bit, if (A) you owe taxes, and (B) you had no withholding (seems likely since you indicate that you're retired), and (C) you made no estimated payments, and (D) the amount left in from 2020 to apply to 2021 taxes is insufficient to cover 2021 taxes, then the form will most likely pop up. It should not compute a penalty if the amount due is under $1,000, but it needs to be computed to determine that no penalty is due. (Note that one of the form issues here, however, is that it is failing to give 2021 credit on form 2210 for 2020 tax overpayments applied to 2021 rather than refunded.)
You can also take a look at the actual 2210 and the little flowchart and checkboxes on the first page, and see if you can determine what may be causing the form to appear. If it still appears that the form is coming up in error, then you can contact the TurboTax help desk to see if they can assist.
Good luck.
