Random glitches are usually small problems that may be readily fixed. If this is the first time Snapchat has malfunctioned, it's most likely simply a hiccup. Most of the time, forcing the program to close and then restart works, so try that first. Here's how you do it:

1. Swipe up from the bottom of your Home screen to the middle and hold until the App Switcher appears.
2. To find the Snapchat app preview, swipe left or right.
3. To clean or terminate the Snapchat app, press and hold the app, then tap the minus (-) symbol.
4. Alternatively, as soon as the minus (-) icon appears on the screen, swipe up to exit the app.