What's causing the Telerik RadEditor to place the CSS "t-no-boxshadow t-no-flexbox t-ie t-ie7" on the HTML element of my page. When it renders like this the styling of the toolbars is incorrect.
I'm running in IE11, but my page is derived from a in-house framework class rather than System.Web.UI.Page. Something in the custom class seems to be triggering the RadEditor to place this CSS on the HTML element.