I have the same issue as Brian Potter on http://stephenwalther.com/archive/2013/04/30/april-2013-release-of-the-ajax-control-toolkit. I have registered AjaxFileUploadHandler.axd in web.config but it makes no difference. I suspect there is a security issues but where? I don't have an App_Data and am trying to save to ~/Images but the error occurs at the start. The upload complete method is not reached.
Comments: Same issue. Works fine for IE, Firefox, Chrome in dev environment (VS2012) but javascript error in IE9 "error raising upload complete event and start new upload" when deployed to a server with IIS7. Works fine with Firefox & Chrome even when deployed. So, it fails only in IE.
Comments: Same issue. Works fine for IE, Firefox, Chrome in dev environment (VS2012) but javascript error in IE9 "error raising upload complete event and start new upload" when deployed to a server with IIS7. Works fine with Firefox & Chrome even when deployed. So, it fails only in IE.