I reinstalled Quicken from the web.
When I tried to open the file I had been working on before the reinstallation, a recent file named all HSHLD94P, I get is ablank screen with Quicken Classis premier in the upper left corner and File and Help. Placing the cursor on the screen I see a rotating blue "busy" indicator, and clicking has no effect. I have to use Task Manager to force it closed.
This happens for various backup files over the last month and also happens when I attempt to restore from _backup files made by quicken. It does open an old file I have from August 2025. It opens a different file - named Rentals.qdf from all dates. The HSLD file that fails 243MB, compared to the HSHLD file that works (215 MB) and the Rental.qdf file (29 MB).
Copying a reduced HSHLD file using the "copy or backup" option in the Quicken program solved the problem!