Rail signals don't work when drones place them.

[Tickstart]

Sorry, missed the [1.1.42] there.

Not sure this is a bug but I see no reason it should be this way. See picture. Right before this I had the two signals closest to the engineer positioned closer to the other signals but thought I'd move them inside the fence to protect the train in case it had to stand there. I ordered the nearby drones to replace the signals, I think I used both Alt-D and ctrl-X from the map view.



You can see the rail signal there, blinking in orange indicating it can't make a block. Which is weird, because it totally should. This has happened before, I remember. Because all I have to do in order to resolve it is to manually travel up there, get out, by hand remove the signal and place it down on the same spot - then it works. My game is 100% vanilla.

[mrvn]

The problem is that you placed the signal wrong.

Check the other signals that do work. They are all placed with the lights alongside the rails. The blinking signal is turned 90° to the track.

You might have copied a signal from somewhere else that had a vertical orientation or rotated it before placing the ghost. This can happen when you copy another signal. If you take a signal in your hand and hover next to a rail the signal should align itself to the rain and if you then shit-click it to place a ghost everything will work. Doesn't work when the rail itself is a ghost though, then you have to manually rotate the signal before placing it.

[Tickstart]

Wow, never realized signals had directions like that. But you're right, that was most probably the issue here. Thanks.

[MEOWMI]

This can happen because drone building allows you to place signals (or stations) in places you're not supposed. Signal rotation is one major trip-up as happened here, another one is that you can place a signal ghost on a tile of track that can't hold a signal (since not all parts of a track are valid for signals even if there's space to place them). These trip-ups don't happen with hand placement because then the game actually checks to ensure the position is valid and also fills in the rotation automatically. Similar story with mixing pipes of different fluids.