A problem with trains

[Bizz Keryear]

OK, I am still fairly new to this game even though I have some 60 hours (~30 on first map + ~30 on second) on the clock.

offtopic comment

I gave up on my first map since it was an island but later repurposed it with the map editor to a custom scenario with all I need to test stuff out, without being bothered by attacks or raiding bases.

On my test stuff map I played around with tracks and trains. (since I never got in a situation to need them (maps set on rich and big resources)
What I don't understand is why the trains think there is no path. All stations are accessible (don't mind the signals I will figure them out once the trains go where I want them to)
(I marked the directions on the picture)
But no matter from where to where as soon as the trains have to go to the center piece they say "no path".

(click imgur image for bigger picture)

[sillyfly]

...
(don't mind the signals I will figure them out once the trains go where I want them to)
...

But the signals are your problem. Every place you have a signal only on one side makes it effectively a one-way section. If you want two-way sections, all signals must be paired (when mousing over one signal, the other one is also highlighted).
Here, for example, is where one of your trains gets stuck in pathing:

image

7VHJhNX.jpg (276.64 KiB) Viewed 11108 times

(Edit: typo)

(Edit 2: Even though I haven't marked it, the bottom branch also has the signal on the left side, so the train can't take that one either)

(Edit 3: I'm too tired to post, apparently. Even if you meant for it to go around the circle and back up north, there is a signal on the left side right after the eastern circle)

[Bizz Keryear]

No worries I got ... to many signals, after I removed the ones for wrong direction it worked.

[Bizz Keryear]

One more problem, though:
The marked signals are freaking out and I have no clue why.

Also: Do I use too many signals here?

image in big

[DaveMcW]

The blinking chain signals are in the middle of the intersection, so they do nothing. You don't need them since you already have chain signals on both tracks leading to the intersection.

[PiggyWhiskey]

One more problem, though:
The marked signals are freaking out and I have no clue why.

Also: Do I use too many signals here?

image in big

The blinking chain signals are in the middle of the intersection, so they do nothing. You don't need them since you already have chain signals on both tracks leading to the intersection.

That's not quite right.
Signals will only blink when it can't determine what track it is on. OP had the signals where they "connect" to 2 tracks. If they are moved outwards by a tile or two, they should come good.
Bizz, you should only put signals before and after any joins in the track, or if you want to break a long length of track into multiple chunks (to allow more trains to use it)
Your flashing signals are flashing because the inside part (not where the light is) is touching another piece of track.
But you don't need them anyway as you have signals on the outbound paths anyway.

If you're trying to be thrifty, you can remove the signals on the diagonal lines (Between normal signals and the flashing ones) as they won't improve the path finding, or be used at all.