I get a milky white screen and a message that "Poser executable file is no longer functioning." I can re-boot Poser and sometimes it's a normal start. ( I've got up to the fifth reboot before I can start work.)

A note on this: Poser does weird things, sometimes, when it crashes, making it's cache a mess and then choosing to reload that cache/settings on a restart. Not sure if it's a memory issue or an actual cache issue. But, the common solution, besides a reboot, is to clear out your computer's cache, either using something like CCleaner or using Windows Cleanup. Either of these will delete unused caches. Run 'em after Poser crashes, the restart Poser.

Also - Make sure you have given Poser adequate permissions. Basically, you need to either run it in Administrator mode or take the time to customize its permissions. If Poser runs into an operation it doesn't have Permission to execute, I could see it stalling out like this.