There are several reasons an action may not launch:
1. The app might not be installed. Starting in iOS 9 Launch Center Pro can no longer detect whether an app is installed it can only try to launch the app.
2. The app is installed, but the developer changed or removed the URL Launch Center Pro used to launch the app. If this appears to be the case, please let us know so that we can remove the URL from our list of supported apps.
3. The action URL may contain errors. If you created the app using the Action Composer, the resultant URL should work, but it's easy to create syntax errors when manually editing an action URL.