Do you have a named display setting with that name now? We took that out of V5 a couple betas ago. If your graphics card supports it, the the Rendered display mode now has Shadows turned on.
If you'be been messing with the settings, then I would recommend going to each page of the definition and clicking the Restore Defaults button. Then have a look. If you want to further tweak the display then go for it.
It made it. In options under "View/Display Modes/Rendered/Shadows " all the sliders are default set to stand to left, and not like under the RenderedShadows setting for shadows. I adjusted it to be the same , and then it works.
I do have a named display setting for both renderedshadows and rendered - see attachment