Today I tried to update one of my Windows Store Apps. When I tried to create an App Package for the Store I got an error. One that was completely new to me.

The certificate specified has expired. For more information about renewing certificates, see http://go.microsoft.com/fwlink/?LinkID=241478.

We’re lucky this time, renewing the certificate is very easy. Just follow below steps (copied from MSDN).

1. In Solution Explorer, open the shortcut menu for the .appxmanifest file, choose Open With, and then choose App Manifest Designer.
2. In the App Manifest Designer, choose the Packaging tab, and then choose the Choose Certificate button.
3. In the Choose Certificate dialog box, expand the Configure Certificate list, and then choose Create test certificate.
4. In the Create test certificate dialog box, click the OK button.

In the end Visual Studio will generate the new certificate with a new expiry date. The new certificate will be valid for a full year.