FumeFX Delete Undefined Light Entries
There is an issue where if you delete a light that is assigned to a Fume Grid without first removing it from the Fume Grid, there will be an undefined entry in the lights.
This is really only noticeable via maxscript.
I created this script to delete all undefined entries in the light list for all the fumes in the scene.
Simply run the script and all the Fumes will be fixed.