Factorio Forums

If you place a curve on top of a track to make a signal flash, it keeps flashing after you remove it and the signal says "No block". Rebuilding the signal fixes it.

Here is a video to show what exactly i mean.
Log file

No mods installed.

A search brought up nothing, i hope this hasn't been reported yet.

The same thing happened to me to, I hope they fix it soon because it could confuse some people

Interesting, just had something similar happen to me but wasn't sure if it was one of my many mods causing it:
After placing a blueprint for a train junction (it has a bunch of signals), one of the signals started flashing incorrectly after being placed by my (modded) bots, but it went away when I placed it in the same spot by hand. Using bots again reproduced the issue, even with all other signals in place. Upon closer examination, it was that specific blueprint causing the issue. Somehow, that one signal wasn't considered to be on the rail it was right next to.

Possibly related to this: when a signal is placed as part of a blueprint but the track part is deleted prior to placing and then manually added, signal will also remain flashing.

Fixed for 0.15.