Working with Levelled Item lists

[ezeepeezee]

So I'm trying to add randomized gear to raiders and talon mercs, but I can't seem to get the editor to save my modifications correctly. Specifically what I'm doing is creating leveled loot list trees, using items from single-item plugins and item compilation plugins. So I make the leveled item form for items and groups, save so that they are recognized in the 'object' list, set them up exactly how I see them set up in other plugins, and when I use the "preview calculated result" function, it works perfectly. My problem comes when I try to open it again, using the exact same plugins - the GECK jumbles everything up and doesn't save non-vanilla items in the records (sometimes replacing plugin items with other lists I made), and when I look at the lists in TESSnip, the items in the lists show one of two errors: Warning: Subrecord doesn't seem to match the expected structure; Item: (formID): FormID was invalid. I have no idea what I'm doing wrong - can anybody help me?

 

Edit: Okay, I think I have this figured out, but there's something else that's puzzling me. I use the junk metal weapons, as well as MMM, as I mentioned. What I don't get is that sometimes super mutants are carrying junk metal weapons (and if I recall so do raiders), but I don't have any plugins that add those items to the loot table. What's up with that?