As I can see you are specifying the RadUploadModule
in your web config, which was needed for the already deprecated RadUpload control. Could you try removing the declaration of the handler in the web.config and test the behavior again. In addition, test the behavior with the RadCompression
disabled. If the above suggestion does not help, I would suggest you to submit a support ticket, with attaching a runnable sample demonstrating the problem so we could inspect it locally.
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