Argh, i knew, i forgot something.... Running on version 11.8.

It's not A. I'm not using any other trains than the normal ones.
An i don't think it's B either. The iron train is stopped as well. Also the red signal in front of the iron train wouldn't be there, if the following block is reserved for this train.

In my current train-heavy playthrough sometimes (approx. once an hour) a train stops at no specific place with the "no path" error. This can of course cause massive jams. Pausing and unpausing the train fixes it every time. No other manual intervention is required. http://i.imgur.com/zIa9K...