Touch ID has disappeared

I purchased a new iMac in the end of November or the early of December last year. Everything worked perfectly well until I added a foreign language on the language bar.

One thing I have particularly noticed that is the Touch ID. It is so convenience and I use it all the time. Two days ago it stopped working and I thought it's because of my dirty finger. Unfortunately it's not. I first deleted my fingerprint and hoped I could reset and reinstallnthe new one. It didn't allow me to do it. I then uninstalled the foreign language input and remove the language bar completely. After all these, the Touch ID in the system preference is gone. Any suggestion please? I have not set up the check point in time machine and really don't want to reinstall the system after using less than two months.