System Preferences won't open from Apple menu

Anyone know a good fix for this?

A few weeks ago, I started noticing that I could no longer open my System Preferences application from the Apple Menu bar (either via the Apple logo > System Preferences, or via WiFi icon > Network Preferences, or even by right-clicking on the Desktop to change the Desktop Background, etc.).

WHAT WORKS:

I can open the System Preferences if I click directly on the application icon or try to open it from the dock.

I can open the application from the Apple menu if I sign in as another user.

WHAT DOESN'T WORK:

The problem doesn't go away when I restart in "safe boot" mode.

The problem doesn't go away when I run Disk Utility.

The problem doesn't go away when I remove the "Finder" and "System Preferences" .plist files from the Preferences folder in the user Library.

The problem doesn't go away when I remove the "Preference Pane" .cache files from the Cache folder in the user Library.

The problem doesn't go away when I zap the PRAM.

The problem does not go away when I replace the System Preferences application from a recent backup.

I was about to just try and re-install the MacOS, but thought I would try the forums first, since the Apple Support site said it should not be necessary if the problem is only limited to one user profile. I found lots of entries in the forums for this issue dated a few years ago, and have tried most of the solutions, but I don't think you can repair disk permissions anymore on El Capitan.

Anyone have any ideas? Thanks.