RadFileExplorer Telerik Error - Getting a System.NullReferenceException thrown from within Telerik RFE tool

[Tyler]

Hi guys,

We are using the Telerik RadFileExplorer tool in our UI and we are getting a consistent bug where every-other sub-folder that gets created generates the following error:

System.NullReferenceException: Object reference not set to an instance of an object.
   at Telerik.Web.UI.RadFileExplorer.CreateFolder(String currNodeValue, String newDirName)
   at System.Web.UI.WebControls.Button.OnClick(EventArgs e)
   at System.Web.UI.WebControls.Button.RaisePostBackEvent(String eventArgument)
   at System.Web.UI.Page.ProcessRequestMain(Boolean includeStagesBeforeAsyncPoint, Boolean includeStagesAfterAsyncPoint)

For example: I create a parent folder with no issues, I then create a child folder and error gets generated, I then create a grandchild folder successfully, I then create a great-grandchild folder and error gets generated, and so on.

There are a few weird things about this: A) the folders are still getting created even when error is thrown (which makes me think it could be a postback event where the error occurs), B) we use different testing environments, and when testing on the smaller-scale environments including localhost this issue is non-reproducible. However, using the same workflow in our larger-scale test environments, as well as in production, this error is reproducible.

Telerik version 2021.2.511.45, .NET version 4.8, Application reads and writes to a network drive.

I'm hoping to get some help with this as there isn't a lot of documentation on the internet for this specific tool, and I only found one article where this same issue was occurring, but the solution of removing some Telerik RFE code in the page load event handler wasn't applicable as we don't use that specific line of Telerik code.

Thanks so much for any help with this issue.

[Vessy]

Hi Tyler,

Thank you for the detailed explanation. You said that the "Application reads and writes to a network drive" - can you share some more details on how you are configuring the permissions of the application? Are you able to create the same sequence of folders (parent-child-subchild) in the application successfully if creating them directly in the code-behind? You can test that using the approach demonstrated in this help article.

The faced issue can be related also to broken AJAX updated on the page. Can you disable temporary the AJAX on the page and see if the behavior is the same? You can do it by setting the EnableAjax="false" property of the AjaxManager and commenting the UpdatePanel/AjaxPanel controls on the page (if any).

If none of the above helps, can you send me a small project containing the whole setup leading to the issue, so I can examine it further at my end?

A FiddlerJam capture of the problem would also provide us some information possibly useful for the troubleshooting, you can see how to prepare such in the Capture issues with Fiddler Jam article.

Looking forward to hearing from you!

Regards,
Vessy
Progress Telerik

[Tyler]

Hi Vessy, 

Thanks so much for your reply. I apologize for the delayed response, I've been heads down on another issue for the last week that took a higher priority. I think I will have some time to work on this today or tomorrow, and I will try the suggestions you mentioned above and let you know how that goes. Thanks again and talk soon.

Best,

Tyler

[Vessy]

Sure, Tyler, take your time and let me know if I can assist you any further on this matter.