'Trade route' on hexes without road/railroad (1.0.0.621)

Unfortunately, I don't know what caused this in the first place. I noticed while trying to minimize my railroad network that my current game considers several hexes to be part of the trade route when they are not.

In the attached save, there are two such spots west of the worker that should be the first unit selected on load. The hexes include two southeast of Yangzhou and one east of Megara (though there are others). The easiest way to see this is using the trade route overlay on the strategic view, though hovering over the tiles also indicates that they're part of the trade network in the tooltip.

I've played additional turns, and the designation stays, so it's not due to a road just having been removed (and in any case, the workers should still be present if that were the case). I'm pretty sure at least in the case of Yangzhou that one of the two 'leftover' route spots is the location of a city that was razed. I suspect that the city tile and possibly any inner-ring roads that are actively part of the network when the city is razed are not cleaned up properly.

Posting some screenshots would have been helpful.

I guess this is your problem and I don't have an explanation.

Yep, those are the tiles.

I'll confirm the problem reported in the initial post. Also, the Trade Route overlay in Strategic View appears to be bugged. It omits many tiles that, I think, should be included. For example, see the attached thumbnail (taken from the save game). The two tiles directly NE from the city of Setia have railroads and the mouseovers show them as having Trade Routes. However, they aren't colored yellow. There are lots of other tiles like this. Has anyone else seen this problem? I wonder if it's related to the problems with huge maps. This particular save file crashed two or three times while I was examining it.

Moderator Action: Moved to the Confirmed Bugs forum.