My mobile phone (Yu-Yuphoria) continue updating OS or optimising Apps and not stop.

Actually last night when I'm going to use my mobile it displayed black screen and then I did restart the phone.

At the time of restart phone as usual display "cyanogen" logo and then instantly going to updating mode and display "Optimise Apps". I gave time but this process is not finish. I also switch off device and switch on but same alway phone going on updating mode and displaying **"Optimise Apps".

I'm facing this issue last 2 days. If anyone have faced same problem then guide me on right direction.

In Short how to stop this continuously updating/optimising OS ?