Here's what I know (and don't).
First, my dialog box did the shakes also. It is asking for the iCloud Keychain PW, not your login to Quicken, TurboTax etc. I called TurboTax and surprise of surprises, was hardly on hold and got tech support. The Rep told me he was NOT experienced with Macs, but would do what he could. He wanted to send a link that would allow him to get on my computer, and I said, sorry, that isn't happening so let's do what we can.
He thought that because I imported last year's return from TurboTax the Mac system was asking permission to share the document. So if that's the case, I said I'll just start a new return from scratch... that didn't help.
We tried a few things like deleting and re-downloading/installing the program. No fix. To be fair, if I had let the tech into my computer he might have figured out the issue, but I wasn't willing.
Finally he gave me a link to download the program directly from TurboTax, for no charge since I had verified to him my receipt and authentication so he knew I had purchased from Amazon. I did download the program from their website, and after a bit did get it running, but I'm not really sure what fixed it, because even the new version asked for the PW.
I did find out that I had to check the "Always Allow" box, otherwise it didn't accept the PW. So, bottom line I don't really know if it was the new download, or the always allow option because while I think I had tried that before I'm not sure. Maybe it was that simple?
Not sure this will help, but it's the best I can do.
