package builds, but installation fails

[salfter]

I thought I'd try out the script by backing up the solitaire app and reinstall from the backup:

.\Appx-Backup.ps1 -WSAppPath "C:\Program Files\WindowsApps\Microsoft.MicrosoftSolitaireCollection_4.9.6151.0_x64__8wekyb3d8bbwe" -WSAppOutputPath "e:\tmp\appx" -WSTools "C:\Program Files (x86)\Windows Kits\10\bin\10.0.19041.0\x86\"

This created two files in e:\tmp\appx. I installed the certificate and then tried double-clicking the .appx file to install. It threw up a dialog, I told it to install, it ran for a little bit...and then failed with the following:

App installation failed with error message: Deployment Add operation with target volume C: on Package Microsoft.MicrosoftSolitaireCollection_4.9.6151.0_x64__8wekyb3d8bbwe from: (Microsoft.MicrosoftSolitaireCollection_4.9.6151.0_x64__8wekyb3d8bbwe.appx) failed with error 0x80070057. See http://go.microsoft.com/fwlink/?LinkId=235160 for help diagnosing app deployment issues. (0x80070057)

I also tried another app and got the same result. Has something changed in newer versions of Windows 10? (I'm running 21H1.)