Factorio Forums

Hi,
In the attached save file the signal that I am standing next to is red when it should not be.
Additionally, the chain signal that the train is stopped at is incorrectly red, as it should be blue.
Signal remains red no matter what I do until I lift and replace the signal.
I will try to recreate as I have a save in the not too distant past.

Ok, was able to recreate it.
All you need to do is build left hand corner and you will see that the chain signal on the corner (that is already placed, but changing colour) will become red. If you lift the signal and put it down again it will correctly become green.

Hi,
I have the same problem since upgradeing to 0.15.10. I keep finding signals that are red when they shouldn't be.
I can attach my save if it's any help.

Can be fixed by replacing the glitched signal. But still, needs looking into.

I just removed a junction from my unloading area and realised that my trains had become stuck because this train is stopped at a signal that's red despite there clearly being no train in the associated block: . Removing and replacing the signal fixes the problem.

I've uploaded my save file as well, hopefully this helps. Merged...

Noticed this yesterday when one of my signals stayed red for some reason. No idea what caused it but it was fixed by replacing the signal. Note that it was only 1 normal signal (no chain) and everything was placed by bots.

same here, Chainsignals placed with Blueprints should can have that problem, perhaps when it's placed before the Rail is set?

I've had this happen multiple times on complicated rail blueprints and in some cases I couldn't figure out which signal might be causing the problem, picking up and replacing all of the red signals didn't seem to do anything.

Glad to see it's not just me experiencing this. I've experienced the rail signal glitching and turning red after selective deconstruction of an intersection. Though I cannot recall if the segment was originally made by hand or bots (probably bots). It still occurs when I selectively deconstruct the T-junction with bots or manually to convert the T-junction into a straight connection.

I've seen this happen multiple times, but usually i just remove and replace the signal to resolve it. Though time, I figured I should reach out and see if I can help. I should also say that I'm using mods, though since I made a game save, I also disabled mods and tried deconstructing and the same issue occurred.

Below are some photos I took of before and after deconstruction of the segment. Please note that no entities were replaced, just removal of signals and rails.

Before deconstruction:
(close-up)
https://i.imgur.com/x7fTUm8.jpg
(overview)
https://i.imgur.com/n7r7lcn.jpg

After deconstruction:
(close-up with red annotations)
https://i.imgur.com/dd3WeJL.jpg
(overview with red annotations)
https://i.imgur.com/EnLHKFR.jpg

I have also made game saves of this before the glitch (normal functioning intersection), and a game save when I see the rail signal not turning green and staying red. If you would like me to post those, let me know and of any other directives.

Cheers,
Biker

Edit - not sure if I should have posted here, or just made a new thread.... First time at bug-related post

I found the same issue. I can give a savegame if needed

I can confirm I have this happen quite frequently when I am tweaking rails (usually when I'm removing rails without changing the signal placement). Removing the signals and placing them in the same spots seems to fix the problem until I start tweaking the rails again.

If it helps, all of my rails with this problem I built by hand using the non-ghost rail placement tool and removed by hand.

Should not happen in 15.11 anymore, broken signals still need to be replaced.

Thank you HanziQ.