Well I had some of the same.
I had Poser open (on a Windows PC, and with the light library selcted.
Went to a filemanager.
Copied Judy obj, textures etc into the respectivaly poser 1-5 folders.
Went to the figures library.
Pushed on the refresh button (arrowed circle) and Poser vanished in a blink of an eye.
No errors, no warning, just "went".
Restarted Poser 8 and all was there and well.
Filed a ticket, but got a " could not diplicate".

Every installation is different.

One thing I found too.
Whatever problem I have; Restarting Poser 8 will often solve the problem.

Poser 1, 2, 3, 4, 5, 7, P8 and PPro2010, P9 and PP2012, P10 and PP2014 Game Dev
"Do not drive faster then your angel can fly"!