papyrus

I tried buying today 2 somewhat expensive hats, on the trade offer screen i spent some time thinking about their worth, but then decided to still buy them. However when i did so a trade error 28 has shown up, i tried cancelling the trade offer outside the offer itself, but instead of showing me my trade offer it instead showed a screen with the message that said "There was an error retrieving your trade offers. Please try again later" wdid?