Last year, Microsoft announced their decision to end the support of the RC4 cipher in Microsoft Edge and Internet Explorer 11 in early 2016. Today, they confirmed that this change will be released as part of April’s cumulative security updates on April 12th, 2016. With this update, the RC4 cipher will be disabled by default and will not be used during TLS fallback negotiations.
If your service is still using RC4, you need make the switch. Microsoft has recommended to enable TLS 1.2 in the web services and remove support for RC4.Check Security Advisory 2868725 for more details.