Loaded our internal dev site and received the titled error. Apparently this happens sometimes when running DotNet 3.0 or 3.5 WCF features on a DotNet 4.0 framework.
"EpicEditor is an embeddable JavaScript Markdown editor with split fullscreen editing, live previewing, automatic draft saving, offline support, and more. For developers, it offers a robust API, can be easily themed, and allows you to swap out the bundled Markdown parser with anything you throw at it. "