Bug found in Simutrans-Experimental version 10.9 and Pak.128.Britain-Ex 0.8.3 (ie latest):
The ship "East Indiaman", which in 1825 is the only sailing ship capable of moving passengers on both rivers and open ocean, refuses to load passengers at a river dock. In spite of this, the game recognises the valid passenger route and passengers arrive and wait at the docks, but the route is incapable of moving any.
On looking at this, I do not think that this is a bug: the East Indiaman has a station tile length of 2, meaning that the (invisible) passenger and mail parts of the ship will not dock at a single tile canal/river stop. Just make your stops longer, and it should work. The East Indiaman is, after all, a very large ship, and needs a sizeable dock!
We learn something every day, I had no idea we had ships in the game that were >1 tile. Glad it was nothing more serious!
Thanks James.
I ran into this before but also never notice that the number of tiles is 2, as shown right in the dialogue. Something to add to the FAQ right after "why won't my train go back to the starting point now that it's loaded..."