Railworks America

I have the bigboy and am trying to add it to a scenario with no luck. I have looked at the Billionaire scenario to see if I have it numbered correctly and all looks well but when I load the scenario the game crashes. I am trying to add it to castle rock route.

Make sure you are puting all 3 parts on it, you have the frontframes, the engine, and the tender

I did that and it still don't work keeps crashing the game. I have added it to a challenger scenario with no problems

If you are trying to swap a steam loco for a diesel engine, it may not work. Some have had success, some not. Seems you are not.

Have you cleared the blueprint cache before you start the game? Don't try and verify the files, it will wipe out any changes you have made! Also, I would recommend cloning the route, then make changes to the clone. Biggest advantage of that is, doing a verify won't change the clone!

I've had success swapping diesel for steam in every scenario on any route.
Use rw tools and replace the diesel with the steam engine. Only swap the engine not the tender. Don't add the tender just yet. Sometimes you might have to use the same number but mostly it doesn't matter. Save your work then go into Railworks in game and choose edit the scenario you just did. When in there, NOW you can stuff that tender in where it belongs. Course if it's Big Boy or Challenger add the front frames too.
I'm a huge steam fan, so I have steamers running in about averything. LOL!
The big trick was to swap the engines only in RW Tools and then add the tender in game and the scenario will never know what hit it.
I've had a rare case or two where it didn't work but found out it was a numbering problem. I eventually get it going anyway.