When the ImageEditor is used in Canvas mode (enabled by default) all modifications applied to the edited image are kept on the client before the saving. This is why the image cannot be directly saved from the server, but you can force the control to pass the editing data to it by using its client-side saveImageOnServer()
method. You can refer this live demo for more detailed information on the subject: http://demos.telerik.com/aspnet-ajax/imageeditor/examples/customsaving/defaultcs.aspx
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