Created attachment 161417 [details]
The example

SUMMARY
***
I wanted to start my electron app (PgAdmin4) with the argument "--ozone-platform-hint=auto", so I decided to edit this application's .desktop file via GUI. 

By the way, instead of adding the argument to the "Arguments" line, I appended this argument to the "Program" line like the way in the attachment.

Then, when I tried to fix it, the whole Plasma crashed. It has been fixed after change the desktop file directly with an editor. (~/.local/share/applications/pgadmin4.desktop) 
***


STEPS TO REPRODUCE
1. Open your panel and find an application
2. Right click, click "edit application" and give invalid arguments in the Program field under the Application tab.
3. Then, try to fix it in the same way.

OBSERVED RESULT
Whole plasma crashed

EXPECTED RESULT
The "Edit Application" dialogue should be opened.


SOFTWARE/OS VERSIONS
Linux/KDE Plasma: KDE Neon 5.27.6/Kernel 5.19.0-50-generic
KDE Plasma Version:  5.27.6
KDE Frameworks Version: 5.108.0
Qt Version: 5.15.10