this is a community build from the previous page , B9 changed a lot from Release4 to Release5 and the original D12 mod author has appeared to disappeared, so nothing has properly been updated or maintained. B9 has also updated since that build was made so there more than a few bugs and incompatible parts on the firespitter issue i would download the most current dll from the firespitter forum, and make sure there is ONLY ONE firespitter.dll in the entire gamedata folder. i don't currently have this installed, so i can't (or really want to) answer any questions you may have. all i can say is to read the last few pages.