I've tested them one by one and i can replicate the exceptions.

And for example, the following train assets just work fine when spawned, they do not generate an exception:
https://steamcommunity.com/sharedfiles/filedetails/?id=465105119
https://steamcommunity.com/sharedfiles/filedetails/?id=465102067
https://steamcommunity.com/sharedfiles/filedetails/?id=471746386
https://steamcommunity.com/sharedfiles/filedetails/?id=529118345
https://steamcommunity.com/sharedfiles/filedetails/?id=471780069
https://steamcommunity.com/sharedfiles/filedetails/?id=500984466
https://steamcommunity.com/sharedfiles/filedetails/?id=581361285

I don't know what's going on, they worked fined up until last game patch.
Just wanted to mention the issue here and hoping that modders can find a solution.
The assets themselves are great!

In all instances, the output_log.txt contains the following message:
281,744ms | Simulation error: Object reference not set to an instance of an object
at Vehicle.CalculateTotalLength (uint16,int&) <0x00281>
at Vehicle.CalculateTotalLength (uint16) <0x00036>
at TrainAI.PathFindReady (uint16,Vehicle&) <0x000c5>
at (wrapper dynamic-method) TrainAI.TrainAI.SimulationStep_Patch0 (TrainAI,uint16,Vehicle&,UnityEngine.Vector3) <0x0009d>
at (wrapper dynamic-method) VehicleManager.VehicleManager.SimulationStepImpl_Patch0 (VehicleManager,int) <0x004d9>
at SimulationManagerBase`2.SimulationStep (int) <0x0004c>
at VehicleManager.ISimulationManager.SimulationStep (int) <0x00024>
at SimulationManager.SimulationStep () <0x00693>
at SimulationManager.SimulationThread () <0x0018a>
[Core]

Currently, this asset as well as other train assets give an 'Object reference not set to instance exception' when they spawn.
Thus far, I've noticed the following assets generate this exception:
https://steamcommunity.com/sharedfiles/filedetails/?id=474346265
https://steamcommunity.com/sharedfiles/filedetails/?id=763894571
https://steamcommunity.com/sharedfiles/filedetails/?id=1289068049
https://steamcommunity.com/sharedfiles/filedetails/?id=501974754

@acc3ss Violation Just want to give you a heads up that the shade of blue that you use on most of your models is off. The correct collour should be the same as on your NS intercity Standard / extra long trains because this is the correct shade of blue

this is for your NS NID series, your SLT series for your NS DD-AR, the Plan V/T trains, your mat 54 series, your Virm trains, your 1700 intercity train and the rest (yes I got them all huge fan)

tof man

Awesome!