When you try to use the RadUpload, the UploadedFiles collection has no files inside.

There are two possible reasons for the problem:

• You have set File Validation and the the uploaded files are considered invalid.

• You are using a Button or other control which causes postback is using AJAX to make an asynchronous postback. This can be because

  • It is placed inside RadAjaxPanel (or UpdatePanel)

  • It has an associated AjaxSetting (RadAjax)

  • It has an associated Trigger (ASP.NET AJAX)

• If the reason for the problem was the File Validation, try adjusting the File Validation properties, such as AllowedFileExtensions, AllowedMimeTypes and MaxFileSize.

• If the reason for the problem was an asynchronous postback, try removing the control that makes the postback (callback) from the AjaxPanel or UpdatePanel, or remove its associated AjaxSetting or Trigger. The Uploading Files with AJAX topic describes additional approaches you can take.

RadAjax, ASP.NET AJAX or any other similar framework for asynchronous calls uses the XmlHttpRequest component to make its callback requests to the web application. This component is not able to upload files.

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