Since KORD works, this excludes any problem with the Addon Manager. In any case, problems with Addon Manager are always because it becomes a victim of too aggressive antivirus products that blocks its execution but in this case it would simply not start (you wouldn't see its menu in fs9), it will not crash at nit only.
You can safely exclude an activation problem: this would revert the scenery to Trial mode, it will never cause a crash, at night only.
Since you already reinstalled the sceneries, this excludes the chance a night texture of the scenery might have been corrupted.
This leaves with only one possible explanation: you might have a problem with something else. THe most likely cause for a crash at a specific time, it's a missing or corrupted texture for an AI airplane. in this case, being at night only, it could be a lightmap.
It might happen with an AI that appears on those sceneries only, but not at KORD, so this might mislead you the issue is in the scenery. Of course, fact the you can't find other reports of this in the forum, seems to confirm the problem is not in the sceneries. But we have other cases of crashes happening at a specific time, and it turned out to be an AI texture.
