Always try these two things first, they solve most general issues. Restart the Device: Restart your device about once a week for best performance. 1. Hold down the power button until a "power off" message appears. 2. Confirm that you want to power off. 3. Allow the device to be off for a minute or two before turning it back on and trying the app again. Uninstalling/Reinstalling App (If restart does not work.) 1. Go into Settings. 2. Select Apps or Applications. 3. Select the misbehaving app from the list, and tap the "uninstall" button. 4. Reinstall the app. If you need instructions on doing this, see the Tutorials page. Apps for Cloud Library - checkouts will reappear after login to the app.