"Application isn't running" errors for System Events

Lately I’ve been getting “Application isn’t running” errors for System Events in some of my scripts. Then during troubleshooting I can’t even launch SE by double-clicking in the Finder; I have to run the executable inside the app package from the command line. I suppose I could add a do shell script line to do that, but I’d have to edit an awful lot of scripts. Any idea what’s going on?

Would be a good idea to to apply what we call here “démarrage sans échec”.
We do that by pressing the shift key during the boot process.
Apply some cleaning with a tool like the free Onyx may be useful too.

Yvan KOENIG running High Sierra 10.13.6 in French (VALLAURIS, France) mardi 28 janvier 2020 18:25:39