With Vanguard, my originally reported error message is what precisely what happens after providing valid account and document entries to the screens you showed, @MarilynG1.
The reason I am posting today is to report that, after waiting for Schwab to notify me that tax documents were finally ready to download (early Feb then late Feb), the import from Schwab to TurboTax desktop worked perfectly, as it had in previous years.
My guess, based on 30 years experience writing web applications and back-end data transfer systems, is that Intuit changed the spec on the error handling, and partners did not keep up with the (likely terribly documented) API changes.
Anyway, if you had trouble with Schwab, try them again. I never got anywhere with Vanguard this year.
Good luck, everyone.
