Basically you’ve entered something that TurboTax doesn’t like, and it gives out a poorly worded error. To resolve this issue, please select everything that is in the SIN box and delete it. Then re-type your spouse’s SIN, making sure to use only numbers and no special characters or spaces. There should be total of 9 numbers.

Here's what worked for me:
- I entered my spouse's SIN (perfecter than perfectly), gave me the error listed above.
- Cleared my cache, logged back in.
- I changed the last digit of her SIN, pressed enter, changed it again, pressed enter (basically went 0-9), no luck.

- Then I entered my SIN, pressed enter, no luck.

- Then I copied her SIN from last years, T1, pressed enter, BINGO.

Dont forget to rub tummy and pat head while spinning in a circle.