On Fri, 06 Nov 2015, Dev Guy wrote:
Hello while using my system with the KDE desktop manager, my system
became unresponsive for about 30 seconds, after I was able to only
move the mouse around but nothing else was accessible. I could still
see all the windows, then both my monitor went black. I had to do a
cold boot to get everything working.
Which version of Debian? Standard install? What's your hardware?
What apps were running at the time? What background processes? Is
this the first time this has happened? Does the problem persist after
reboot?
How can I enter this bug using reportbug? I don't know what actually
caused the entire system to lock up.
Sounds like a run away process. Have you checked system logs? Dmesg?