IE8: MultipleFileSelection and UploadedFilesRendering="BelowFileInput" Error

[Peter]

I'd been experiencing problems in IE8 when using multiple file selection, selecting >1 file in browser dialog and then immediately cancelling either uploadING files or files pending TO BE uploaded.  IE would throw an exception detailed below which would then break client side scripting.  The silverlight plugin is being used by IE.

After a lot of diagnosing I identified it to due to a possible bug caused by using multiple file selection with the UploadedFilesRendering="BelowFileInput" option on the control.

I managed to replicate this issue by testing the multiple selection example which initially had no issues cancelling files.  Then when the UploadedFilesRendering="BelowFileInput" option is added cancels are broken as described (attached broken example for reference).

Please advise if there is any workaround for this issue as I still require the layout to be such that the uploaded files are listed below the file input.  Thanks in advance.

IE exception:

Webpage error details

User Agent: Mozilla/4.0 (compatible; MSIE 8.0; Windows NT 6.1; WOW64; Trident/4.0; GTB7.5; SLCC2; .NET CLR 2.0.50727; .NET CLR 3.5.30729; .NET CLR 3.0.30729; Media Center PC 6.0; .NET4.0C; InfoPath.3; .NET4.0E)
Timestamp: Tue, 15 Oct 2013 14:18:33 UTC


Message: System.NullReferenceException: Object reference not set to an instance of an object.
   at System.Windows.Browser.ManagedObjectInfo.Invoke(ManagedObject obj, InvokeType invokeType, String memberName, ScriptParam[] args)
   at System.Windows.Hosting.ManagedHost.InvokeScriptableMember(IntPtr pHandle, Int32 nMemberID, Int32 nInvokeType, Int32 nArgCount, ScriptParam[] pArgs, ScriptParam& pResult, ExceptionInfo& pExcepInfo)
Line: 12625
Char: 1
Code: 0
URI: http://localhost:56236/RadControls_AspNetAjax/Telerik.Web.UI.WebResource.axd?_TSM_HiddenField_=ctl00_QsfScriptManager_TSM&compress=1&_TSM_CombinedScripts_=%3b%3bSystem.Web.Extensions%2c+Version%3d4.0.0.0%2c+Culture%3dneutral%2c+PublicKeyToken%3d31bf3856ad364e35%3aen-US%3ac9cbdec3-c810-4e87-846c-fb25a7c08002%3aea597d4b%3ab25378d2%3bTelerik.Web.UI%3aen-US%3a4401a8f1-5215-4b97-a426-3601ce0fa0ff%3a16e4e7cd%3af7645509%3b%7c%7c%3a2de754c%3a3ae6d49e%3a368ab121%3a38dcf56c%3a812a75b1%3a845d48ec%3bTelerik.Web.UI%2c+Version%3d2013.2.717.45%2c+Culture%3dneutral%2c+PublicKeyToken%3d121fae78165ba3d4%3aen-US%3a4401a8f1-5215-4b97-a426-3601ce0fa0ff%3a86526ba7%3a874f8ea2%3aa1a4383a%3a24ee1bba%3a1e771326%3aeaae47ab%3a7165f74%3a2003d0b8%3af46195d3%3ae524c98b%3a628ebdd0%3aed16cbdc%3a19620875%3a3f6e8f3f%3a68f76a79%3a52af31a4%3a2a2fc429%3ae330518b%3a8e6f0d33%3a6a6d718d%3aa7e79140


<%@ Page Language="C#" MasterPageFile="~/MasterPage.master" %>
<%@ Register TagPrefix="telerik" Namespace="Telerik.Web.UI" Assembly="Telerik.Web.UI" %>

<asp:Content ID="Content1" ContentPlaceHolderID="head" runat="Server">
</asp:Content>

<asp:Content ID="Content2" ContentPlaceHolderID="ContentPlaceHolder1" runat="Server">

    <telerik:RadProgressManager runat="server" ID="RadProgressManager1" />

    <div class="qsf-demo-canvas">
        <%-- For the purpose of this demo the files are discarded.
             In order to store the uploaded files permanently set the TargetFolder property to a valid location. --%>
        <telerik:RadAsyncUpload runat="server" ID="AsyncUpload1" MultipleFileSelection="Automatic" UploadedFilesRendering="BelowFileInput" />

        <telerik:RadProgressArea runat="server" ID="RadProgressArea1" />
    </div>

</asp:Content>

[Hristo Valyavicharski]

Hi Peter,

What version are you using? The pasted code seems to be working fine with the latest. Watch this video to see how it behaves. 

Regards,
Hristo Valyavicharski
Telerik

[Peter]

Thanks for looking into this for me.

Your screencast doesn't appear to show cancelling the files while they are uploading or TO BE uploaded?

Try selecting number of large files, preferably using remote/non-local instance of the upload page so they don't instantaneously complete, and cancel files while they are uploading or pending TO BE uploaded.  You should see the exception appear in the status bar.

I have recently updated to the latest version "RadControls for ASP.NET AJAX Q3 2013" aka build 2013.3.1015 and have retested and still experience this issue.

[Hristo Valyavicharski]

Hi Peter,

Thank you for the clarification. I managed to get the same error as you. As you probably know the RadAsyncUpload uses Silverlight upload module for IE8. Unfortunately the issue is caused by the Silverlight plugin, which we cannot modify. To resolve the issue set DisablePlugins property to true. This will force the RadAsyncUpload to use the IFrame module. Note that in this case MultiFileSelection will not work.

Regards,
Hristo Valyavicharski
Telerik

[Peter]

Yes need multiple file upload so unable to use that option.

Sorry I don't understand why the asyncUpload silverlight plugin can't be modified to resolve this.  Yes I get that its not end user resolvable but can telerik not acknowledge this as a telerik bug and resolve in a future hotfix/release?

[Hristo Valyavicharski]

Hi Peter,

I have logged this issue into our internal tracking system. Here you can monitor its progress.

Regards,
Hristo Valyavicharski
Telerik