RadUpload Ajax callback erro.Source url returned invalid content

[Abhay]

Hi,
I am working on application in which we are using Rad Controls.
When we open appliaction in two browser window, we got 'RadUpload Ajax callback erro.Source url returned invalid content' error.

[Vijayaraj]

Add these two handlers in your web.config.
<httpHandlers>
<add verb="*" path="Telerik.RadUploadProgressHandler.ashx" type="Telerik.Web.UI.Upload.RadUploadProgressHandler, Telerik.Web.UI" />
</httpHandlers>

<handlers>
<add name="Telerik.RadUploadProgressHandler.ashx_*" path="Telerik.RadUploadProgressHandler.ashx" verb="*" type="Telerik.Web.UI.Upload.RadUploadProgressHandler, Telerik.Web.UI" preCondition="integratedMode,runtimeVersionv2.0" />
</handlers>