I saw this bug in earlier games, but I thought it was doing something wrong. I would have a trader come in, I would attempt a trade and even though I was offering substantially more in goods, they would refuse. After that, their goods get stuck in the trade office. The traders would lease, more traders come, and even though they are in the office with their goods it will say "no trader in depot". In the attached save, the iron cogs I attempted to trade for with the last traders didn't get stuck in the office like in previous games. However, after unsuccessfully trying to trade for the iron cogs with the previous traders, I can no longer trade. It wasn't a huge deal in the temperate bio dome, as I could work my way up to making most things, in the harder, cold bio dome, it makes the games very difficult when you can't get the things you need and can't yet make.