I had the same issue this morning.
Go back to the beginning where you see the steps "My Returns" then click "My Info" then you need to start from the beginning in that area. click marital status and do all steps you will find the donor question at one point need to answer then you can file
This issue will be fixed shortly- for now you can go to "My Info" click on (Name) Canadian Citizenship and make sure that you answer the questions " Do you authorize the CRA to share your name and email address with the Government of Nunavut to contact you about organ and tissue donation, and to maintain the organ and tissue Donor Registry?
This happened to those who transferred from last year.
Thank you for choosing TurboTax.
What do I do if I receive error code xml when trying to net file?
Please select My Info, then Province of Residence from the left side menu (≡). Continue through the pages and make sure you answer the question “Do you authorize the CRA to share your information with Elections Canada to update the National Register of Electors?” for both you and your spouse (if you have one).
Then you can select File > CRA Online Mail from the left side menu (≡) and continue on through there to try to NETFILE again.