Default [Q] prob with credential storage password

Hi there,

I have a prob with my galaxy s4 after updating for android kitkat 4.4.2...
I was about to set a new VPN but I have a message tells me to enter credential storage password, I haven't set one ever and I don't even know what that is...
I've surf the web lookin' for solution but no answer..
I don't have PIN or Pattern lock or any thing else, just swipe..
please help...
regards