Are you running a newer version of Poser on an old system? Are you running an older version of Poser on a new system? Does your system meet the recommended system requirements?

When you purchase a Poser figure, the merchant should list what required products (M4, H4, M4 Morphs++) you need to have installed in order to use their product. If you're getting the error, it's probably because you're missing one of those things. As for the program freezing, even if you get an error, that shouldn't normally happen, so something may be less than ideal with your system. If it's an older version of Poser, you may try running it in Compatibility mode for an older version of Windows?

(also, if it's an old used box version you got from somewhere, you might also wanna check and see if there was a patch released that would fix some of the stability issues)