Works on my MAC 10.9.5 with Photoshop CC (2014 .2.2). You're probably running Yosemite, which by watching this forum, is full of problems.
Yes I am.
Filter > Render does work on Yosemite. If the choices are grayed out, try this:
The 3D menu must be operational on your system. At least 512 MB vram needed
File > New to create a new file
3D menu > New Mesh from Layer > Postcard
Then go into Filter menu Render > Tree and it should go from Grayed out to black and work.
You can close the file. From now on it will work.
Thanks, but New Mesh is greyed out.
Make the new file a floating layer, then try it again from the 3D menu or
Try "New 3D Extrusion from Selected layer"
How much vram is being reported in Preferences > 3D?
More on this problem Re: Picture Frame and Trees greyed out