What version of Poser are you using ?
What figures are in the scene ?
Do you have "Use external binary morph targets" turned on ?

The quickest way to check for a binary morph problem, is to move the associated PMD file to a different directory from the PZ3 and try to open the scene.
If you don't have a PMD for the PZ3, the problem isn't the binary morphs.
If the scene now loads, see this thread -> http://www.renderosity.com/mod/forumpro/showthread.php?thread_id=2717864