Check in your web.config file if all handlers are registered correctly and make sure that there is no '/' before Telerik.RadUploadProgressHandler.ashx
. If everything looks normal then try to send us runnable sample or paste a code snippet here, so we can try to isolate and debug this behavior.
Do you use ProgressArea? There are some limitations
related to it. When an application is using RadUpload control with RadProgressArea and is deployed on IIS server the progress indicators are not working. The issue appears only when you open a web site e.g. http://localhost/testpage/ and the Default.aspx (the Default.aspx file is the default document of the application) file is opened and the URL is without Default.aspx. If you open e.g. http://localhost/testpage/Default.apsx URL the RadProgressArea is working correct. The issue appears because of the HttpRequest object.
the Telerik team
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