For those of you who like me have had trouble with the "Delete lights" scripts working with certain lightsets and scenes....

I've recently made a discovery that resurrects these screwed-up .pz3s!   What had been happening is once I click the script, some of the lights appear to be deleted, but the preview window goes completely white, and any figures/props that were visible are completely invisible. I used to give these scenes up for dead, and start over from scratch.

On a lark, I saved one of these scenes after deleting the lights. Lo and behold, upon reopening, there is my scene, non-corrupted, with all the lights deleted, ready for new lights, or perhaps a few old lights that I can manually delete.  Oh joy!

Just to clarify:  I have had this problem with every version of the "delete lights" script I could find, including the one that comes with P6, and every version of Ockham's script that I could find. I'm not implying there is a problem with the scripts.  The problem seemed to occur because instead of deleting the lights before I applied a new set, I used to just click on a new light set.   This seemed to create some hybrid of the old and new, and the script would sometimes have a hard time deleting this hybrid. I think it also has something to do with certain lightsets using "point at" or something - ? Not sure about this.

If you've got some messed up scenes laying on your hard drive, you might try this and see if you can resurrect them. I've just saved myself a lot of work in rebuilding a lot of scenes!

If you're curious about this problem, do a search for "delete lights" and you'll find thread about this.

This only happens to me sometimes, not always, after I delete lights and put new ones in. I was really disconcerted the first time it happened. I went ahead and did a 1/4 size render (which showed up) and was pleasantly surprised when all my stuff appeared where it was supposed to after that. I can't figure out why it happens sometimes, and sometimes not, but most of the time when it does happen it's because I've been deleting lights and clicking tabs really fast. It might not be that for sure, but that's been my observation.

This problem often (maybe not always) comes from missing parts

in the light set (LT2) file. 

If the author built the LT2 by copying and pasting sections

of a simpler file, he generally fails to include those ShadowLiteCam

thingies.  One ShadowCam must match each light.

When Poser deletes lights manually, it seems to handle

missing Cams. But in Python the missing cam causes a problem.

An LT2 that was made by creating and setting all the lights inside Poser

and then saving to library, will always work properly.

Interesting! Thanks Ockham, I didn't realize Python could misread the light settings.