I have been having loads of trouble with the Consignment Store in Twinbrook. For the past sim week, none of my items in the store have sold. Everyday at 5pm I wait for the message to pop up saying I sold something, but it never does. So I go back and cancel my items so they don't lose value. Then the next day I go back and put the items back up between 8am-3pm, then when 5 o'clock rolls around, still nothing.
My sim had been doing so well selling thousands of dollars worth of sculptures but now nothing has sold for at least a week. I've tried shutting down and restarting but still nothing sells.
Does anybody have any advice on how I can get the store to work again?

I had this same promblem until Sims Wiki updated. Basically just cancel the consignment and delete it through your inventory manually those items. That some how resets it. For more information just type in Cosignment Store in Sims Wiki :).