I just recently upgraded to v15.1 from 14.1. I put an HTML editor on a simple page in design view the editor looks fine.  But I run the page and get this...

[FormatException: Index (zero based) must be greater than or equal to zero and less than the size of the argument list.]
   System.Text.StringBuilder.AppendFormat(IFormatProvider provider, String format, Object[] args) +10930219
   System.String.Format(IFormatProvider provider, String format, Object[] args) +63
   Infragistics.WebUI.WebHtmlEditor.WebHtmlEditor.RenderEndTag(HtmlTextWriter writer) +5791
   System.Web.UI.WebControls.WebControl.Render(HtmlTextWriter writer) +43
   Infragistics.WebUI.WebHtmlEditor.WebHtmlEditor.Render(HtmlTextWriter writerForIE) +1006
   System.Web.UI.Control.RenderControlInternal(HtmlTextWriter writer, ControlAdapter adapter) +57

I cannot get the version updater to run.  I entered a note on that as well.  I have made sure all the scripts and images are loaded under ig_common in the inetpub\wwwroot\aspnet_client\system_web\4_0_30319\ig_common directory.  I don't know where to go from here.  Please advise.