The status of this response is Pending and require some modification by the author.
If your device is rooted, it is very critical to access applications on the device. Once the device gets rooted, it is difficult to install new apps. Only a few apps can be accessible, but you can't update those apps. Rooting the device becomes crucial for accessing it normally. It is very difficult to update the operating system. So, you need to flash your device with Samsung Kies or mobile Odin pro versions. When the device is flashed, you will lose the control of root access. The mobile looks like newer for use. It allows you to re-root your device.
Currently, you had rooted with King User. You need to remove the King User root application from your device. Open the settings of the app, click the 'Root authorizing setting'. You will find the 'Remove root permission’; there you will see the un-root status. Enter the clear button to proceed with the un-rooting. Once the un-root is completed, you will be required to restart your device for completion.