I upgraded my Windows Phone 8.1 Store App project to the new Universal Windows Platform following this guide. After some minor errors everything looks good so far except this error:
Validation error. error C00CE169: App manifest validation error: The app manifest must be valid as per schema: Line 16, Column 21, Reason: '12345.User.MyAppName' violates pattern constraint '[0-9a-fA-F]{8}-[0-9a-fA-F]{4}-[0-9a-fA-F]{4}-[0-9a-fA-F]{4}-[0-9a-fA-F]{12}'. The attribute 'PhoneProductId' with value '12345.User.MyAppName' failed to parse.
Step 4 from the guide I used states:
For Windows Store only: You need to add a <mp:PhoneIdentity> child element to the <Package> element. Add a PhoneProductId attribute and a PhonePublisherId attribute. Set the PhoneProductId to have the same value as the Name attribute in the <Identity> element. Set the PhonePublishedId value to: 00000000-0000-0000-0000-000000000000.
This is exactly what I did, but my Name attribute of course doesn't match the pattern that is (now) expected. I also read here that PhoneProductId matches to the ProductId of the published Windows Phone 8 app, but either this is the same as I used above (not quite sure) or I can't find it (looking at my app's details on the Developer Dashboard on MSDN).
How can I fix this without losing reference of my upgraded solution to the app already published?
To make your Universal Windows App link to your already published Windows Phone 8.1 app, put your Windows Phone 8.1 ProductID and PublisherID that you can find in your AppxManifest.xml (or the Package.appxmanifest in Visual Studio), in the Universal App's corresponding PhoneProductId and PhonePublisherID in the element.