The onAppInstall event expects renderData() callback method called for both success and error scenarios to complete the app installation.
Since the app install functionality cannot wait forever for the app to return the callback, the platform will wait 10 seconds for a response and fail if the renderData() is not called.
Could you check the event handler for the onAppInstall event call the renderData() callback in all the conditions, and ensure it is called within 10 seconds of execution?