Factorio Forums

This is an issue that mostly occurs with modded inserters (such as Bob's), as diagonal inserters ar not available in the vanilla game. However as far as I understand the problem isn't caused by the mod itself.

As seen in the attached picture, inserters that are diagonally in front of a cargon wagon (or 2 tiles behind) are not unloading when a new train arrives. However if I add an inserter or change it settings after a train has arrived, it works temporarily until the train leaves and next one comes.

I think there is actually 2 related issues here. First is that the area where inserters get notified about the train's presence only reaches 2 tiles before and after the wagon. Second is that whenever there is a wagon or locomotive in front of another, the "notification area" gets partly overlapped by the one in the front. You can see this when a wagon is being pushed in front a train; the inserters that are 1-2 tiles in front of the wagon are now working unlike in the picture's situation.
There is an obscure case where this can be seen with vanilla long inserters as well. When the inserter is near a track curve it can unload directly from behind a wagon/locomotive. But another wagon connected to it prevents it. If I remove the wagon the long inserter works normally.

This should be fixed for 0.15.