I am getting same issue trying to import.
Using my "Stash" account number and SSN as password
I also tried my "Stash" login and SSN as password
Neither seem to work.
Stash is not currently on our list of TurboTax Import Partners. You will need to upload your form from your computer or type it in yourself. Please see this TurboTax Help Article for more information.
I had the same issue. This is what I did to get it to work. Import your Stash info from the 1099-DIV or 1099-INT section, whichever is applicable for you. In my case, I had Dividends as well. It accepted my Stash account and SSN and then showed it had 1099-DIV and 1099-B items to import.
Thank you. I tried again today and I was able to import successfully.
Used my stash account number and ssn and it completed.