Kde

Probably what happened was that a file in:

$HOME/.kde/share/config[<version>]

was corrupted. So, with KDE not running, rename that directory to like.

$HOME/.kde/share/config.save

and restart KDE. This will destroy all you your configurations and you will go back to the defaults. But you can restore most of them by copying the files from the "config.save" directory to the new one that is created when you restart KDE. Sort them by date and restore the ones that were at least an hour old when it crashed first. Restoring newer ones is a risk and you need to decide if you want to risk it.