Since we wanted everyone to be able to play with Traincraft during holidays, we might have missed some things, this I guess was one of them. If you’re getting a “nullpointer” crash, or just a crash in general when you start your world, just re-download the mod now from the same links, and you should be good to go.
A word of warning, due to inventory changes, we suggest and urge you to clean out your freight wagons, so not to loose any items that are inside.
You can read the changelog here.
Sorry for the trouble. 😉