I'm having a crash of the pasma-desktop process every day at about 10am. The computer is never used at that moment (I'm always at work at that moment or sleeping during the weekend ).

I see that the process has been restarted looking at the start time of the process and also I can find a line in the .xsession-errors file that say: "KCrash: Application 'plasma-desktop' crashing...".

But I cannot debug it in any way, because the process is stared (on KDE startup and after every crash) with the argument "--nocrashhandler".

Does anybody knows a way to get more info about this crash? Maybe disabling the "--nocrashhandler" option or adding a "--debug" option or something like that, but I don't know how to set options for the pasma-desktop process.

You need to provide more information. What distribution are you using? What version of KDE? What widgets do you have on your desktop and panel? Have you tried closing plasma with "kquitapp plasma-desktop" and then launching it from a terminal with the command "plasma-desktop"? (no quotes in either case) Make sure you leave the terminal open.