That fork is right on the station exit. That's apparently close enough to cause this train to fail out of a fuel stop for a fork in the track- then instantly route back to the same station, so the "fork in the track" message is flickering. Makes it somewhat difficult to click on if I don't pause the game.

Reproduction steps:

1. Have a fueling station, configured as a fuel stop in a train network.
2. Put a fork in the track right at the exit, with precisely 0 track segments between the station and the fork. If there's 1 or more track blocks after the station, but few enough for it to still fork-out (seems to be 1-2, it occupies 3 straight segments when properly stopped), the train will drive in circles (and run out of fuel) instead of spamming the error.
3. Optional: Pause all other fueling stops, so this is the only valid one on the network. Makes it faster.
4. Wait for a train to run low on fuel.
5. Watch the fireworks!

Version 4.1 | v0.8.4b (b593)