I loaded "by hand" 100 woods on wagon train, which is assigned to trade route. On next town on trade route message appears: "... unload 100 woods ...", but there is no woods on town nor on wagon train. There is enough space to unload 100 woods on town.
Please load one of the latest save files and see in you can reproduce this behavior. If you haven't saved explicitly, look at the autosave directory.
If you can't reproduce the bug, most likely developers can't either and hence they can't fix it.
If you can reproduce this bug, please attach your save file and log file (FreeCol.log).
Last edit: forgesourcer 2020-10-06
Attached last save file - just before this case.
A little more detail would have been helpful here, but I am assuming you are referring to the wagon train in Jamestown with the RUDA trade route. The problem here is that you are trying to do something trade routes are not designed to do. The RUDA route says to load ore at Barbados, or more precisely, go to Barbados, unload everything except ore, load ore, then go to Jamestown and unload everything, then back to Barbados. Trade routes only transport what you have told them to. If you load random stuff onto a trade route unit, it will just get dumped again unless the loaded goods match what is to be loaded at that colony.
So, not a bug. If you want to send lumber to Barbados on a trade route, set lumber to be loaded in Jamestown. You can limit the amount sent with the warehouse export setting. Or use a non-trade route unit.