Hi,

 

I think that is a server side exception when the uploader try to call the MS-Ajax postback.

 

Please try this to confirm it :

 

<script>

function CuteWebUI_AjaxUploader_OnPostBack()

{

alert("The file is uploaded , there will be a server error soon.");
}

</script>

 

Please post some screen shot too..

 

Regards,
Terry