Hi Mulberry! and welcome to the SUBSIM forums.
It's obvious that you have a conflict with another mod. Have you tried disabling your other mods ( one at a time! ) to see which one is tripping up your RDF install?
A strong contender would have to be Flakmonkey's Twisty-Periscope-Thingy...if you are running that mod.
I use Anvart'S RDF system and I know that this is not compatible with TPT without modification. Well to be absolutely correct...it doesn't work "out of the box" with the two versions Reece so kindly put up ( btw Cheers Reece
), although it
may be OK with Flakmonkey's original. Unfortunately this was withdrawn before I could get hold of it, so I'm not certain.