Simulation error Object reference not set

Symptom

Both of these must be true:

• While loading a saved game, an error message appears:

  • Simulation error: Object reference not set

• On reviewing your log file, the stack trace mentions:

  • RoadBaseAI.CanEnableTrafficLights

Cause

This is a bug in the game itself, not TM:PE.

This problem occurs when your saved game includes a road asset which is no longer available, usually a result of one of the following:

• You unsubscribed a road asset

• You unsubscribed a mod that provided the road asset (such as Network Extensions)

• The author of a road asset (or mod that provided one) deletes their workshop item, which also removes it from your game

Solution

• Quick fix: Subscribe and enable Safenets mod

• Otherwise, see: How to Remove Workshop Networks

Was it Fixed?

If not, it's likely your save game is lost, sorry.

Something else? See: 👉 Troubleshooting