Unhandled Exception occurring

I'm using version 4.4.1.14. I've gotten this exception on servers that were upgraded from 4.4.0.5 and from a server that was a brand new install of 4.4.1.14. I get this exception after logging in and going to Settings -> Languages, Validation Messages, and Misc. Text.

the RadControls folder was not found 
Description: An unhandled exception occurred during the execution of the current web request. Please review the stack trace for more information about the error and where it originated in the code. 

Exception Details: Telerik.WebControls.RadEditorUtils.RadControlsDirNotFoundException: the RadControls folder was not found

Stack Trace: 

[RadControlsDirNotFoundException: the RadControls folder was not found]
   Telerik.WebControls.RadEditor.CheckRadControlsExistance() +207
   Telerik.WebControls.RadEditorRenderer.Render() +14
   Telerik.WebControls.RadEditor.Render(HtmlTextWriter output) +164
   System.Web.UI.Control.RenderControlInternal(HtmlTextWriter writer, ControlAdapter adapter) +25
   System.Web.UI.Control.RenderControl(HtmlTextWriter writer, ControlAdapter adapter) +121
   System.Web.UI.Control.RenderControl(HtmlTextWriter writer) +22
   System.Web.UI.Control.RenderChildrenInternal(HtmlTextWriter writer, ICollection children) +130
   System.Web.UI.Control.RenderChildren(HtmlTextWriter writer) +24
   System.Web.UI.WebControls.WebControl.RenderContents(HtmlTextWriter writer) +7
   System.Web.UI.WebControls.WebControl.Render(HtmlTextWriter writer) +29
   Telerik.WebControls.PageView.Render(HtmlTextWriter writer) +367
   System.Web.UI.Control.RenderControlInternal(HtmlTextWriter writer, ControlAdapter adapter) +25
   System.Web.UI.Control.RenderControl(HtmlTextWriter writer, ControlAdapter adapter) +121
   System.Web.UI.Control.RenderControl(HtmlTextWriter writer) +22
   System.Web.UI.Control.RenderChildrenInternal(HtmlTextWriter writer, ICollection children) +130
   System.Web.UI.Control.RenderChildren(HtmlTextWriter writer) +24
   System.Web.UI.WebControls.WebControl.RenderContents(HtmlTextWriter writer) +7
   System.Web.UI.WebControls.WebControl.Render(HtmlTextWriter writer) +29
   Telerik.WebControls.RadMultiPage.Render(HtmlTextWriter output) +191
   System.Web.UI.Control.RenderControlInternal(HtmlTextWriter writer, ControlAdapter adapter) +25
   System.Web.UI.Control.RenderControl(HtmlTextWriter writer, ControlAdapter adapter) +121
   System.Web.UI.Control.RenderControl(HtmlTextWriter writer) +22
   System.Web.UI.Control.RenderChildrenInternal(HtmlTextWriter writer, ICollection children) +130
   System.Web.UI.Control.RenderChildren(HtmlTextWriter writer) +24
   System.Web.UI.Control.Render(HtmlTextWriter writer) +7
   System.Web.UI.Control.RenderControlInternal(HtmlTextWriter writer, ControlAdapter adapter) +25
   System.Web.UI.Control.RenderControl(HtmlTextWriter writer, ControlAdapter adapter) +121
   System.Web.UI.Control.RenderControl(HtmlTextWriter writer) +22
   ASP.checkboxadmin_master.__RendermainForm(HtmlTextWriter __w, Control parameterContainer) +457
   System.Web.UI.Control.RenderChildrenInternal(HtmlTextWriter writer, ICollection children) +2065851
   System.Web.UI.Control.RenderChildren(HtmlTextWriter writer) +24
   System.Web.UI.HtmlControls.HtmlForm.RenderChildren(HtmlTextWriter writer) +59
   System.Web.UI.HtmlControls.HtmlForm.Render(HtmlTextWriter output) +68
   System.Web.UI.Adapters.ControlAdapter.Render(HtmlTextWriter writer) +18
   Checkbox.Web.UrlRewriting.FormRewriterControlAdapter.Render(HtmlTextWriter writer) +36
   System.Web.UI.Control.RenderControlInternal(HtmlTextWriter writer, ControlAdapter adapter) +2065537
   System.Web.UI.Control.RenderControl(HtmlTextWriter writer, ControlAdapter adapter) +121
   System.Web.UI.HtmlControls.HtmlForm.RenderControl(HtmlTextWriter writer) +37
   System.Web.UI.Control.RenderChildrenInternal(HtmlTextWriter writer, ICollection children) +130
   System.Web.UI.Control.RenderChildren(HtmlTextWriter writer) +24
   System.Web.UI.Control.Render(HtmlTextWriter writer) +7
   System.Web.UI.Control.RenderControlInternal(HtmlTextWriter writer, ControlAdapter adapter) +25
   System.Web.UI.Control.RenderControl(HtmlTextWriter writer, ControlAdapter adapter) +121
   System.Web.UI.Control.RenderControl(HtmlTextWriter writer) +22
   System.Web.UI.Control.RenderChildrenInternal(HtmlTextWriter writer, ICollection children) +130
   System.Web.UI.Control.RenderChildren(HtmlTextWriter writer) +24
   System.Web.UI.Page.Render(HtmlTextWriter writer) +26
   Checkbox.Web.Page.LicenseProtectedPage.Render(HtmlTextWriter writer) +257
   System.Web.UI.Control.RenderControlInternal(HtmlTextWriter writer, ControlAdapter adapter) +25
   System.Web.UI.Control.RenderControl(HtmlTextWriter writer, ControlAdapter adapter) +121
   System.Web.UI.Control.RenderControl(HtmlTextWriter writer) +22
   System.Web.UI.Page.ProcessRequestMain(Boolean includeStagesBeforeAsyncPoint, Boolean includeStagesAfterAsyncPoint) +1896

I can't say I've tried 100% of the application pages, but this is the only place I've encountered the exception so far. I'm still doing some digging but I thought I'd post this if there's a known cause.

[pwiesner]

This is an issue we have seen in a limited number of installations. We worked with Telerik and they have suggested the following resolution.

1. Confirm that RadControls folder is located at the root of your installation.
2. Confirm that the correct read permissions are set for the folder and all of its contents.

If the above is true proceed to the next four steps:

3. Open <Checkbox Root>\RadControls\Editor\Dialogs\blank.html in a text editor.
4. Delete the contents of blank.html and replace it with <root></root>
5. Save your changes.
6. Reset IIS or Recycle your application pool.

Please let me know if you have any further issues.

Interesting fix. I had to do all six steps. It worked on all servers.

As a side note, I did not have this issue on one of our servers. The primary difference between the server that worked and the servers I applied the steps to is internet access - the exception occurred on the servers that cannot make outbound requests.

Additionally, I found that if I just deleted the first line of that file, it worked.

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">

Hope this info helps!

EDIT:

I did confirm that in my case, the web server is attempting an outbound HTTP request to W3C for the DTD.