Fix Alt+PrintScreen Shortcut for Current Window Screenshot not working

Today, I was trying to get the screenshot of the current window and found that the Alt+PrintScreen was not working. The solution for this problem is as below:

To solve this problem, you need to do as following:

$ sudo gedit /etc/sysctl.conf

Just add the following line in this file.

kernel.sysrq = 0

This should solve the problem. Hope this helps. :)