Without knowing more about system specs I can’t say for sure - but I see this behavior when scenes start to reach the limits of Poser’s available memory. I rarely see it on 64 bit machines running 2010 or 2012, but regularly far outstrip the capabilities of my 32 bit machine. Sometimes setting the option to Render in a Seperate process will help, and if you have a Pro version you can try “Render in Background” or “Render in Queue”.
Sometimes this is just a render hiccup, and stopping the render and trying it again will work.
If you are on a 32 bit machine or using a 32 bit version of Poser and have a scene with lots of content (or if Poser has been running excessively long without being turned off - like days) then likely you are running out of memory and the renderer is unable to render (possibly unable to even load).