HDR TONING ONLY WORKS ON A FLAT IMAGE
As cool as the new HDR Toning feature is, there is still one little caveat. You can only apply to a flattened image. Meaning no layers. It will prompt you to flatten the image if you try. Also it will not work on a smart object. Believe me, we tried. Best thing to do is apply the image in a duplicated flattened version and then drag into your layered document.
I have a sugestion, a best way is to duplicate the layer, then convert this duplicate to smart object, double click the smart object little icon in the layer corner to open the pbx file, now apply the HDR toning to this smart object. when you finish, you will end with a hdr smart object and with your original in the same document….hope this help..