I tried to merge to HDR in Photoshop CC 2015 using three photos selected from Lightroom and had several issues:
First was I could not see the image unless I switched to 32 bit mode.
After ding that and changing back it would not allow me to preview the photo, I would have to save and see what it looked like in Photoshop. Unfortunately that means you have to start from the beginning if the result required some adjusting which it most often does.
Any setting I am missing to get the preview working?
I don't think Lightroom allows 32 bit viewing, unless it's turned on, the way you did. View the photos in Bridge.
Moving post to Lightroom forum.