Error 1047: An update cannot support fewer languages than the previous app instance supported

New App Hub is Mango-ready and multiple language support is the most sought after feature.  To allow this, any new application or an existing application update needs to do some changes in the project properties.  So if you try uploading an update, or a new application you would face one of the following errors

• Error 2003: The [NeutralResourceLanguage] attribute is missing on the entry assembly.
• Error 1047: An update cannot support fewer languages than the previous app instance supported.
• Error 1048: A language supported in this XAP conflicts with a language that is already supported by another app instance for this app.

Now the solution,

• If you are submitting a new app you will have to manuall add a line in AssemblyInfo.cs file to specificy default language. Something like: Since it was not required for old apps it creates confusion.

  [assembly: NeutralResourcesLanguageAttribute("en-US")]
  

• If you are submitting an update to your exsiting app, you will find that even after adding the above like you will get error like:

  1047: An update cannot support fewer languages than the previous app instance supported.

  To solve that you need to change the language to “en” from “en-US”. Since earlier update did not have this attribute it apparently defaulted to “en”.

And, compile your project and submit it to Marketplace.

More information? Please visit MSDN link