Lua error

Have a lua error everytime i start the game and press sandbox game

Step() failed!: string "–CCarCalculator_Weight.Lua
attempt to index field ‘ChassisMaterial’ (a nil value)

What happend was i was designing a car and when i was done i press save, then i saw the year was 2014 for the car and wanted to change that to 1994 a press save again, then i got a lua error.
Unfortunately im not 100% sure that the lua error i got was the same as the one i got now, didn’t read it i just press try again and now i can’t play sandbox.

Will try to reinstall the game to see if that fixes it.

Please try to just delete the platform and model from your Documents/Automation/Platforms and Documents/Automation/Models folders, that should do the trick.

What if the platform doesn’t shows up? I’m having exactly the same problem…

Edit : I solved the problem, it was just a model error.