Not able to change screen lock type in Android phone

If you are not able to change "screen lock type in an Android phone like Samsung, here is one of the ways you can check and fix it. 

=> Go to Settings, Search "Device Admin Apps" in the settings screen, and check which app is enabled. If you find anything enabled, disable it. Then come back and try removing or changing the screen lock type and it will work fine now. 

- Rahul