Why won't this train path?

[Xgkkp]

I've been tearing my hair out trying to work out why this train won't path. The save is at https://www.dropbox.com/s/hm8npa3d3g6zy ... NoPath.zip, and an image of the setup is below.

I've had problems with this pair of stations before and know it's complex - simplifying the layout worked once, but I've since tried to make both stations one-way and in the real save there are terrain constraints. All the signals seem fine, and none are indicating bad signal placement. Even if I move the train manually to "Position B" - in the same block as the station - it cannot find a path. I've also tried configurations with a signal placed on the split before the station (at S).

What is going on?

Factorio_badTrain.jpg (392.3 KiB) Viewed 1702 times

[twepy]

I couldnt see it from the screenshot, but after loading the savegame i found the issue. The station is placed at a invalid location and its "not connected" to the track and the train can find a valid route to it. I moved it one unit down to a green marker and it working fine.

[Xgkkp]

Thanks, such an easy thing to miss as the graphics totally look fine.

To be clear to anyone else: The curved track out of the station started just in front of the station, so though it looked fine at first glance the station actually wasn't connected.

I wonder if it's worth having a location-warning for stations that aren't connected.