Heres what I add in Base.rte/Index.ini:



I keep getting an error. Someone mind posting a fix?

What is the error?
You might want to take the two slashes away from the first line.

Try looking into the index.ini inside the ventilationset.rte file. It probably refers to more then just that one ini, and that one will need stuff from the other.
Aka, there's probably another file in the same folder that has necessary stuff in it.

Quick Question on this topic is there anyway to get all of my Mods to work while in Scene editor?

Nope, it knows that if you did that and one of those mods were to go missing for whatever reason, you'd get an .rte abort. II you want to make an epic scene with load of stuff from loads of different mods, you'll just have to put everything you want in the one mod folder. It's good practise.