The application that hosts MIME Viewer may crash when you open an XHTML file that contains W3C or DTD content
You have an Extensible Hypertext Markup Language (XHTML) file that contains World Wide Web Consortium (W3C) or document type definition (DTD) content. When you open the file by using Multipurpose Internet Mail Extension (MIME) Viewer, the application that hosts MIME Viewer may crash. Additionally, CPU usage is high.
For example, when you open an XHTML file by using Internet Explorer, Internet Explorer may crash.
For more information on this issue, including potential causes, workarounds, and resolutions, see: Microsoft KB Article KB2514307.