Sold some TF2-keys which are still stuck on my trading bot. It's cluttering up the inventory so I can't send more to it (TF2 items). Also tried to look around for backpack expander, I haven't found any topic about that so figured I might as well ask here.

Backpack expanding requests: https://dispenser.tf/forum/view/5724/

Sometimes it is caused by buyers not accepting the trade offer.