Les Bently screwed up ang got it wrong! :sad:

Here is the corrected version.

If any lights or shadow cams in the two sets share the same internal name and number (which is quite likely), then I don't  think Acadia's method will work. Here is how to combine 2 sets, you will have to get your hands dirty hacking files in a text editor. The nub of the matter is that no two lights or associated shadow cams in a scene can share the same internal name and number, and all the lights must be added from one lt2 (light) file.

Make sure you have Poser set NOT to use compressed files in your General Preferences. Delete the 3 default infinite lights. Load the first light set, save a light set to the Lights pallet as "A". Open a new scene, delete the infinite lights, load your second light set, save it as "B".

Open the light file you saved "A.lt2" in a text editor. You should find it under the path:

.Poser #RuntimeLibrarieslight[some folder]A.lt2

Use your editors search and replace function to do a case sensitive search and replace of all instances of these text strings:

"camera " (note the trailing space) with "camera A" (there is a space before the "A").
"Camera " (note the trailing space) with "Camera A" (there is a space before the "A").
"light " (note the trailing space) with "light A" (there is a space before the "A").

Open B.lt2 in another text editor window, process it the same as the last file, except use "B" in the replace strings, so replace:

"camera " (note the trailing space) with "camera B" (there is a space before the "B").
"Camera " (note the trailing space) with "Camera B" (there is a space before the "B").
"light " (note the trailing space) with "light B" (there is a space before the "B").

Delete the opening brace and version block from the start of the "B.lt2" file, this bit:

{

version
 {
 number #
 }

Then delete the very last brace in the file, the closing "}". Select all the text, and Copy it to the clipboard.

In "A.lt2", scroll to the end of the file, insert a new line just above the closing brace. Into the new line, paste the contents of the clipboard. Save the file back to disk with a new name. You can now delete the "A.lt2" and "B.lt2" files.

This seems to work for me in P4 and P6, I see no reason why it should not work in P5.