You are about to change the signing certificate for the Security Token Service. Changing the certificate to an invalid, inaccessible ...

You are about to change the signing certificate for the Security Token Service. Changing the certificate to an invalid, inaccessible or non-existent certificate will cause your SharePoint installation to stop functioning. Refer to the following article for instructions on how to change this certificate: http://go.microsoft.com/fwlink/?LinkID=178475. Are you sure you want to continue?