Earlier on in the Windows 8 development cycle, apps had a checkbox in their app manifest indicating whether the app should be capable of receiving notifications. Later, that explicit requirement went away from the UI in the app manifest window. Thanks to a discussion with a Microsoft DPE (Development & Platform Evangelism) guy yesterday, I was steered towards using a version of the server-side notifications code that includes full diagnostics. My notifications were being sent, but had a “dropped” status, indicating they weren’t making it to the client app. The client app was running. So why, why, why wasn’t it working?
It was then that a little searching online turned up recommendations to check if the app had permissions enabled to receive notifications. Opening the XML for package.appxmanifest (by right-clicking on it and selecting “View Code” or select the file and hit F7), I was able to just add ToastCapable=”true” to the VisualElements tag. That took care of it.