Apple Store Error 20.
Good thought David! I worked this problem out with the help of Apple support. Your way might have been quicker than their way, but I'll share their way anyway.
But first, I'll note that you are right. The system was confused, whether because profile confusion or something else, the update notice didn't work because there wasn't really an update to download. And Apple support believes the allow download selection issue is irrelevant.
We reset things with the following process.
- Add a new test admin profile.
a. Open System Preferences.
b. Click Users & Groups.
c. Click lock icon to unlock.
d. Click +.
e. Select Admin from New Account dropdown.
f. Enter test (or anything defining and simple) at Full Name, Account Name, and Password.
g. Click Create User.
h. Lock and close.
- Click Apple (top left) and select Log out of... (current profile).
- Login to test (or whatever you named your new profile).
- Open/Launch Apple Store.
- Login to your Apple profile.
- Click Updates & check for downloads.
- After confirming there are no downloads, logout of test, and return to regular profile.
- Confirm that you no longer are notified of waiting updates or that you can install.
- Return to System Profile>Users and Groups.
- Remove test profile.
- Praise WhidbyTomas for his brilliant reporting.
PS, the name would be Whidb
EyTomas, but for an inalterable typo.