[Some websites are not loaded in all my browsers. when I quit, my KSK, it works.]

As instructed in live chat, I uninstalled and reinstalled KSK. But problem still exists.

 

The only workaround for now is to exit of KSK.

 

 

I suggest for you to update your Operating system and then if problem still exist, do some basic troubleshooting such as opening it through a browser, clear cache and cookies/browsing history.