If all your entries agree with the actual 1099-R, there is no way to tell for sure why you are getting a error message.
Your only option at this point is to delete that 1099-R from your tax file and re-enter it very carefully.
See: How do I delete forms in TurboTax Online?
After deleting the 1099-R and any associated
worksheets, log out of the program. When you log back in, use the Delete a
Form tool (List of Forms in My Return) to confirm they have been removed
from your return. Then, go back to the Retirement Income and Social Security
interview to add the 1099-R back in.
If you continue to get an error, update this post with a comment and additional details.
