I use steam, and checked my mods folder, and the mods were not there. I've tried deleting local files and re-installing. I've tried verify game cache. Nothing works.

I used the ingame mod downloader to get some mods. But upon trying to launch the game, it gives me "Error in assignID, fluid with name 'gas-natural-1' does not exist." And the game doesnt launch, preventing me from accessing the ingame mod manager. I use steam, and checked my mods folder, ...