When submitted your Windows Phone 8.1 Silverlight app to the Windows Phone Store , there are times when you get the below error
The package identity associated with this update doesn’t match the uploaded appx: <Guid>
When submitting the app in to the store , you should take care of the package identity name and the Windows Publisher Name in the Windows Phone store with the one available in the XAP package.
You need to login to the Windows Phone Store account and visit the dashboard . Select the App for which you want to upload the XAP file and from the App info section you would see the information about the app.
You need to get the Package identity number and windows publisher and copy it to the respective section in the Package.appxmanifest file under the Identity section.