Why is this always shown to me?

I wanted to use my cell phone again after a year (Huawei, a bit older, I think P5 or so). Now I get time and time again when starting up "20 of 195 apps are optimized / Android is started" that is there for about 20 minutes But nothing happens, after about 20 minutes the cell phone goes off and no longer turns on until you remove the battery and put it back in again. Why?

The operating system will be shot up because the cell phone did not get all the updates properly after the year. I would reset the cell phone and start again…