The Bing Webmaster team recently received feedback that our APIs were intermittently failing, and we deeply regret any inconveniences caused from the API failures. We recognize the frustrations that this may have caused. Upon investigation, we discovered a technical glitch which led to API call failure that is now resolved. We are very grateful to you, our users, who brought this to our attention and thank you for your continued feedback and support.

We’re Listening

Bing and Bing Webmaster Tools are actively listening to you and we value your feedback. It’s important to how we continually improve Bing and to help notify us of potential issues. It’s easy to provide feedback: just look for the Feedback button or link at the bottom of each page. It’s in the footer or the lower-right corner and it looks something like this:

We are using advances in technology to make it easier to quickly find what you are looking for – from answers to life’s big questions or an item in an image you want to learn more about. At Bing, our goal is to help you get answers with less effort. We appreciate your feedback and the more that you can send, the more we can use it to improve Bing. Have a suggestion?

Tell us! The more feedback the merrier.

Please let us know.
The Bing Webmaster Tools Team

Source: Intermittent Webmaster Tools API Issues Resolved | Webmaster Blog