As more websites use HTML5 and 3rd party controls that use HTML5, we do not want users to view this in the browser’s compatibility mode as these elements will to show. Most websites require users to view the page in compatibility mode to be rendered properly. However, this is not a problem today as most browsers are equipped to view the website using any browser without problems. However, if you have just transitioned to newer web technologies and your users are used to viewing your site in compatibility mode, then this is the solution to your problem.
Here’s a quick guide to determine if your users are running IE in compatibility mode: Â http://www.codeproject.com/Articles/820863/How-your-web-site-can-determine-if-the-user-is-run