Nero 2019 does not support playback of commercial protected Blu-ray discs. There is no Nero Blu-ray Player anymore.
If you are playing a blu-ray disc which was burnt by Nero Video or any other non copyrighted blu-ray disc, you could drag the disc to MediaHome. MediaHome will play the .m2ts files in the disc.
If you are playing a blu-ray movie, we are sorry to say Nero software won't be able to play it anymore.