Please attach your savegame too, assuming the problem persists over a save and load.

I attached my save to the original post. Unfortunately, I have AIs in the game, but I wouldn't guess that they would be the ones producing the issue? It seems to persist through loading.

At least you can resolve the situation by clicking the "ignore signals" button on the train, it continues into the depot then. Still, it's weird how this has happened, I'll try to examine that a bit more.

Thanks for that tip! I had written off the save file, so it's nice to know I can continue.

Also, I was able to replicate it a second time: when placing a one-way path signal on top of a train which is entering a depot and the default placement is in the opposite direction that the train is going, it will cause the bug.

This always happens when you put a pathsignal over a train that enters the depot - it is very repetitive.

Steps to reproduce

• build tracks to the depot
• put block or pre signals on it
• send a train to the depot
• when the train entering to depot, put a pathsignal (any direction) in front of this depot - the train will stop

It may not be a good idea to ignore the signal. It is better to change the direction of the train twice.

Something about freeing the track reservation looks suspect, especially this comment on line 2252 of train_cmd.cpp:

/* Can't be holding a reservation if we enter a depot. */

I think it's simply not freeing the reservation, and thus fails when trying to reverse it again after the signal is placed.

EDIT: That function clears the path in front of the train, so is irrelevant, I think. It does try to reverse the path ahead, but that won't work because the depot is still reserved, so it marks it as stuck.