Ah, ok. I was putting in only the Realplume file. I'll try using the Realplume and Realplume-stock file. If that doesn't work, I'll try only the Realplume-stock file. I don't use RealFuels either.
What is the difference between realplume and realplume stock in the download? Last time I have tried to download this, it did not work. does having both of them in the gamedata folder for ksp make it not work?