Kubuntu: Some applications don't start from the Application menu

I faced an issue with my Kubuntu when I could not start some applications from the Application launcher (for example Postman and Chromium). It looked like that nothing happened when I tried to execute an application. Despite this, the application could still be started from the terminal without issues. I tried to figure out what had happened but without luck. Today I finally fixed the problem. I still have no idea what was the root cause, but it looks like some system update consequences..

I found the next article

• https://unix.stackexchange.com/questions/403066/cleaning-up-kde-application-menu-applications-kmenuedit-menu

where the author faced some similar issues after some upgrades. The solution for his cases was the remove of the next file, so the system re-create it

• ~/.config/plasma-org.kde.plasma.desktop-appletsrc

So I tried the same, I just moved that file to the backup and then rebooted the system

After the reboot, all the desktop settings like the panel location and widget configuration were reset. But the Application Menu started to work as expected.

In the next 15 minutes, I restored the panels and widgets configuration, and everything just worked fine. Finally after 6 months of pain.