When attempting trade (https://dispenser.tf/trade/165337/) the bot does not send a trade offer.
I and the bot have the items required.
Upon clicking Purchase and then Proceed, a status bar in the browser appears for a split second, saying "Queuing" and disappears.

The trade is working here. You might probably want to check your trade offer URL, because it is saying "This Trade URL is no longer valid for sending a trade offer to pauliux00." when I try to send you a trade offer.