The appearance of disabled inputs in the markup is not updated in IE11. For the time being you can manually set the corresponding disabled CssClasses, using the approach from this help article: http://www.telerik.com/help/aspnet-ajax/formdecorator-troubleshooting-input-appearance-is-not-updated-when-disabled-in-internet-explorer.html
deleted by rsargent
Hi, please could we have an update on when this is due to be fixed?