What device do you own? What Android version is installed on the device? Did you try clearing the app cache (you can do that in Settings > Apps > choose the app that doesn't work > Storage > Clear Cache)? If clearing app cache didn't work, did you try clearing app data (you can do that in Settings > Apps > choose the app that doesn't work > Storage > Clear Data) or reinstalling the app? Note: clearing data of an app will restore its original state, i.e. the way it was when you first installed it.