Zidoo introduced a new system library libzidoomusic2.so with Music Player v6.9.3. I’ve copied libzidoomusic.so and libzidoomusic2.so from firmware Z9X v6.0.60 to my Z9S and it didn’t boot anymore. I’ve had to recover it.
For now I guess the modded Music Player v6.7.6 is the latest working version for Android 7.1 based Players.
I’ve no idea about the Android 6 based Zidoo Players.
Would be great to get feedback if the modded APKs are working for you and if you want me to continue providing them.