Why isn't this rocket launcher script activating?

I'm trying to use the original ROBLOX rocket launcher for a game I'm making, however it doesn't seem to work with FilteringEnabled. The Rocket script that gets inserted into the rocket does not activate, causing the explosion to not work. I've been Googling and experimenting for hours to no avail. Does anyone have any ideas on how do fix it? The model is here.

Thank you!