When trying to update the OnBoard App through the App Store, you get a message saying it is Unavailable

Very rarely, when attempting to update the OnBoard application through the Apple App Store, you may get a popup saying the application is unavailable. The message is misleading and has to do with the App Store itself, not the application you are trying to download. 

To resolve the issue, turn off the iPad, and then turn it back on. This should clear any App Store connection issues and allow you to update the OnBoard application.