Windows store won't update or install app - Error 0x80070005

[Squeeky]

I'm using Win 10 Pro - Build 19042.1266

Generally, I have no difficulty with the Windows store. However, the store was showing an available update for EarTrumpet, and each time I tried to update it, I received the error message 0x80070005 (Error code 0x80070005 means Access denied and it usually occurs because of lack of permissions).

I tried to uninstall my current version / reinstall. I successfully uninstalled, but upon the attempted reinstall, I get the same error message. So now I have no EarTrumpet at all. Not the hoped-for result.

Solutions?