I've had this happening with a couple of Poser scenes (.pz3) made in PP2014.

I didn't find out what was causing it, but I found a work-around:

• Load the scene in question
• Do >not make any modifications<, and best keep your hands off the mouse and other controls all the time...
• Now save the scene by a different name
• Close Poser, then restart it and load your previously saved (new) scene.

Unfortunately I didn't have neither time nor motivation to solve this glitch because the work-around was all I needed.

And, I'm no paid dev team member, so it's not >my< job to solve this, but >theirs<.

K