"Object reference not set to an instance of an object." during Async Upload

[Adam]

I'm using a file manager control with AsyncUpload enabled:

<telerik:RadFileExplorer ID="expTCDrive" runat="server" EnableCopy="true" OnClientFileOpen="OnClientFileOpen"
                EnableFilterTextBox="true" EnableFilteringOnEnterPressed="false" Width="750px"
                OnClientFolderChange="OnClientFolderChange" Height="500px" EnableAsyncUpload="true">
                <Configuration MaxUploadFileSize="52428800" />
            </telerik:RadFileExplorer>

From time to type, we are receiving the following exception

Error in: https://oursite/ourfolder/Telerik.Web.UI.WebResource.axd?type=rau

Error message: Object reference not set to an instance of an object.

Stack trace:    at Telerik.Web.UI.AsyncUploadHandler.ProcessRequest(HttpContext context)

   at Telerik.Web.UI.HandlerRouter.ProcessHandler(String handlerKey, HttpContext context)

   at Telerik.Web.UI.WebResource.ProcessRequest(HttpContext context)

   at System.Web.HttpApplication.CallHandlerExecutionStep.System.Web.HttpApplication.IExecutionStep.Execute()

   at System.Web.HttpApplication.ExecuteStep(IExecutionStep step, Boolean& completedSynchronously)

Any ideas why this would be happening? I've tried several different things and was hoping that I could recreate it, but I can't. I was thinking that perhaps it was being caused by the Upload button being enabled while it was still uploading in the previous version, but with the latest release, that issue has been fixed and the error still occurs. If it helps, I can package up the entire project and send it as a support ticket.

Thanks,
Adam

[Dobromir]

Hi Adam,

We are not aware of such problem and you are the first one to report it. Could you please provide more detailed information on the specific scenario?

• Which version of RadControls for ASP.NET AJAX and .NET Framework are used in the application?
• Under which browser and its version the problem occurs?
• Are you using custom content provider?
• Could you please provide a simple fully runnable project with reliable steps for reproducing the problem so we can investigate it further?

Looking forward to hearing from you,
Dobromir
the Telerik team

[Adam]

I'm using the latest version of the controls, Q3 2011 SP1. We are running the .NET 4.0 framework.

I do not know the browser the user was using.

Yes, I am using a custom content provider. It is the one that you used in your examples.

I will open a support ticket with the project and also the file they were attempting to upload.

I'm not entirely sure, but I think the problem might have something to do with a slow internet connection and large file size.

Thanks,
Adam

[Dobromir]

Hi Adam,

I already answered your support ticket on the subject. For convenience I will paste my answer here as well:

Thank you for the provided sample project. I tried to reproduce the problem locally but to no avail.

As you assume in the forum thread on the subject, the problem might be caused by the slow internet connection causing the execution of the upload process to timed out and the context object to be expired already. To exclude this option, could you please try to increase the executionTimeout property of the httpRuntime in the web.config?

Have you tried to increase the value of the executionTimeout property? Does it solve the problem?

Greetings,
Dobromir
the Telerik team

[Adam]

We currently have the executionTimeout set to 360 or 6 minutes. I hate to increase it, but it appears that it might be necessary. I'll try doubling it again and see if I get any more exceptions.

Thanks,
Adam

[Rohan]

Hi all,

How can I  Add custom field to File explorer upload window with file explorer  EnableAsyncUpload="true".

I am able to add the custom field to file explorer’s upload window without EnableAsyncUpload.

Using FileExplorer1.Upload.OnClientAdded = "addTitle";

[Vessy]

Hi Adam,

You could get a reference to the AsyncUpload control by replacing "Upload" with "AsyncUpload", for e.g:

FileExplorer1.AsyncUpload.OnClientAdded = "addTitle";

I believe you could find useful information about the custom fields in AsyncUpload in this forum tread.

Greetings,
Veselina
the Telerik team

[Rohan]

Hi all ,

Thank you very much ............. for you support ....