Every app submitted to the Windows Store will be validated by Microsoft before being listed. Part of that validation process involves running the app through an automatic certification tool that Microsoft has included with Visual Studio. You should check that your app passes the certification tool before beginning the Windows Store submission process.
Ensure the SplitApp project you were using in the Packaging your Windows Store app recipe is working correctly and has been deployed.
For the certification process to work, your deployed version must be in the Release mode.
The following steps need to be performed in order to validate your Windows Store app:
