If you encounter errors while uploading app packages during the app submission process, you must resolve them before you can submit your app to the Store. The error message will indicate what the problem is and what you might need to do in order to fix the issue. Here are a few pointers to additional info to help you resolve these errors.
Package type errors for Windows Phone 8.1
When you are updating apps that were previously published for Windows Phone 8.1, you may encounter errors related to package types. For more info about package type requirements, see Maintaining package compatibility for Windows Phone 8.1.
Failure to follow these requirements will result in package upload errors that will prevent you from completing your submission.
Version number conflicts
For info about resolving errors related to version numbers and the requirements when submitting updates, see Package version numbering.
Additionally, be aware that if your submission has more than one Windows Phone 8.1 XAP, they must have the same version number.
Note For additional questions related to other error messages and help with resolving them, please visit our forums.