Bing last week updated it's webmaster API by introducing a new Breaking Change only for users of the Webmaster API that are using the SOAP protocol but not for Users of the Webmaster API using the JSON or POX/HTTP protocols. In other case they will recive an error message such like as...
Bing obviously recommends to update the service reference of your application to fix the this issue. You can do this by right-clicking the service and clicking Update Service Reference.
If you are affected by this issue, you will receive the following error:Error code: UnknownError HResult: 0x80131501The change was due to cause of SOAPAction header value and the namespace URI to make correction, that was previously erroneously set to http://tempuri.org/IWebmasterApi and now is required to be http://schemas.datacontract.org/2004/07/Microsoft.Bing.Webmaster.Api/IWebmasterApi.
Bing obviously recommends to update the service reference of your application to fix the this issue. You can do this by right-clicking the service and clicking Update Service Reference.