unable to cast from youtube to Samsung Smart TV

I cannot now cast from youtube to Samsung Smart tv,whenever I select the cast tab from Google Chrome,it now displays no devices found.

I changed my device name to cast a few days ago on Samsung Smart TV because I had problems screen mirroring from my tablet to Samsung Smart TV as well.

I have just updated Google Chrome,please resolve this issue as soon as possible for me.I am very grateful indeed.Thank you.