KDE Plasma is currently affected by a bug. When you launch an application from the menu, and that application requires to be opened
inside a terminal window (i.e. when opening a pentest tool), KDE will throw an error saying that konsole (the kde terminal emulator) was not found.
Konsole is properly installed and it works, and the error appears only because of such bug.
You can still launch console applications by opening the terminal emulator and launching them from it.
We are sorry for the inconvenience and we are waiting for Debian to import the patched KDE version.
We will release updated ISO files as soon as the bug is closed in Debian.
Everything in the system works as usual, and broken installations will receive the proper updates as soon as possible.
This bug does not affect the MATE release, and we suggest to temporarily download it instead.