Looks like your device doesn't support hardware acceleration of HEVC main 10 profile. Maybe you can enable it manually from HW+ Video Codec & try again in HW+. But, It's not advisable as force attempting an unsupported codec may result in a crash.
VLC play hevc easily ...but i am reset setting mx player and again HW+ setting but not sucessfull .....S7 Hardwarer are strong...but ......