Did so and it did the same thing on the fourth trade....I traded some supplies to do trades with neighbors to see if that would help...I am showing unable to trade with neighbors that are found but ok with others. I did a double check to make sure I had enough supplies to trade. If I leave the trader and go back in I can trade then.
Supply means in the game the tool kids. It is not possible to trade with this sort of supply, exception is the Wholesailer.
My English is not good enough, so supply can be the same as steel or marble.