Go to Settings, Moore, Security, go down to the bottom of that screen and hit Clear Credentials.
A program which was downloaded or installed on your phone after you purchased it installed some type of credentials which prevented you from being able to remove your PIN or pattern.
I had the same problem and struggled with it for several months. I followed standard Samsung procedures and published YouTube videos to remove my screen lock and go back to a swype but had no luck. The options which for supposed to be highlighted including the None option we're not highlighted but once I cleared the credentials, the None option was highlighted and I was able to remove the Screen Lock.
It is so nice to be able to access my phone and not have to enter that "darn" pin every single time ☺
Posted via Android Central App