First off, I have little experience with DNN. Recently I upgraded a working DNN6 site (that I “inherited”) to DNN9. The upgrade ran fine and everything looked fine except for pages with a “LeftMenu” control. On pages with a LeftMenu control, the other controls (e.g. textboxes) were displaying fine but they were not returning newly entered text to the codebehind.
I am using IE11 and I noticed these pages work in Chrome and Firefox. If I run with the debugger in IE and set the mode to IE 10 the page also works.
These pages are setup to use a page theme, “DarkKnight - Double-Menu”. I have other pages that work in IE11 that use a page theme of “DarkKnight – WidePage”. These pages using “WidePage” don’t include “LeftMenu” and work fine under IE11.
When I load a page with LeftMenu in the debugger I get an exception:
SCRIPT438: Object doesn't support property or method 'attachEvent' File: Telerik.Web.UI.WebResource.axd, Line: 5465, Column: 7
The script is in a method: b.RadPanelItem.prototype._attachEventsToTheHeaderElement.
The script is trying to call: e.attachEvent("onclick", this._onExpandHandleClick);
Here, “e” is an HTMLSpanElement. I know that attachEvent is not supported in IE11; addEventListener should be used. So why is this calling attachEvent?
Is there a bug in the script in Telerik.Web.UI.WebResource.axd or is there some old file from DNN6 that is causing this error. Something else? I am stumped.