Indeed we haven't tested the RadUpload and RadProgressArea under Azure yet. In standard case, in order for RadProgressArea to appear, you should declare RadProgressManager on the page in the following order:
RadProgressManager, RadProgressArea and RadUpload. When submit the page, if a file is selected, the progress area will appear. No additional logic is needed.
If a small file is selected for upload, the upload is really fast and the progress area shows for less than a second. Please make sure that the uploaded file is big enough.
the Telerik team
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