1. For a few seconds, press and hold the Power button until the Slide to Power Off command displays.
2. Then, to totally shut down your iPhone, move the power off slider to the right.
3. Press the Power button again after 30 seconds, until the Apple logo shows.
A soft reset has no effect on any data stored on the internal memory, hence no data is lost. When your iPhone has finished rebooting, relaunch the Snapchat app. The problem should be gone by now unless you’re dealing with a more intricate or complex system error.