This is because the drive belt has failed. This belt connects the motor spindle to the paddle spindle. It is most likely worn and slipped off the spindles. To make the bread-maker work again you need a new belt. Before considering a repair you need to do 2 things.
1. Find out if a replacement belt can be obtained for your bread-maker model.
2. Find out of the base/bottom panel can be removed from your bread-maker to replace the belt.
Some bread-maker manufacturers make it very difficult to remove the base/bottom panel. Others are easy to open.
Hope this helps!
ed1vel1, September 2013