When I click on Snapchat is says": "Use your camera? Taking snaps requires access to your camera" and I confirm but can't take a photo anymore like I did before.
This happens when the camera is being used by another application. First thing to do is to press HOME button for 3-4 seconds to bring up the Task manager. Slide the apps to left or right in order to close them and then open Snapchat and take another photo. Additionally, reboot the phone because this process clears the opened instances of the camera device as well.