It worked for me - even if it didn't make sense. The pop-up telling me I had a train already dispatched on my farm 5 was sooo confusing - I have NEVER had a train on that farm - ever. I had JUST unloaded my train on farm 9, bought 2 new freight cars, placed them on farm 9 with the other cars, when - ooops - the message telling me I couldn't dispatch popped up. Following Raul's guidance, I moved my train and all of my cars to farm 5. When I hooked them up there - I had 3 cars that showed up as needing unloaded. I did that, moved them back to my farm 9 and they now work as they should.
The longer I am here the more I appreciate the mods and the devs, esp Raul - for working hard to keep things working as well as they do - glitches and all