So, just as question states. Android device monitor is not showing anything in the File Explorer view. This is only occuring on Virtual Devices running Android API Level 24
A workaround using the adb
command line tool:
root@mypc ~ $ adb kill-server
root@mypc ~ $ adb start-server
root@mypc ~ $ adb root
Now you can browse through the file system using the linux ls
command:
root@mypc ~ $ adb shell ls -all /
total 3688
drwxr-xr-x 15 root root 0 2017-04-21 11:11 .
drwxr-xr-x 15 root root 0 2017-04-21 11:11 ..
drwxr-xr-x 29 root root 0 2017-04-21 11:11 acct
drwxrwx--- 6 system cache 4096 2017-01-06 12:11 cache
lrwxrwxrwx 1 root root 13 1970-01-01 01:00 charger -> /sbin/healthd
...
-rw-r--r-- 1 root root 4853 1970-01-01 01:00 ueventd.rc
lrwxrwxrwx 1 root root 14 1970-01-01 01:00 vendor -> /system/vendor