1. If you use it for too long and your body is too hot, it won't work.

2. The machine is broken, so you need to contact customer service.

There's probably nothing wrong with it, except that the toaster just stirs for a few minutes and needs to wait for fermentation, and then it will run again in a few minutes.

(I met the third situation on the weekend. I used the newly bought ACA MB600. After stirring for 5 minutes, it stopped. I was shocked. As a result, I started working again five minutes later. Then I tried again. )