Unable to access “My Drivd”

Error mounting /dev/sda6 at /media/ububtu/Media Center: Command-line `mount -t "ntfs" -o "uhelper=udisks2,nodev,nosuid,uid=1000,gid=1000,dmask=0077,fmask=0177" "/dev/sda6" "/media/rolindroy/Media Center"' exited with non-zero exit status 14: The disk contains an unclean file system (0, 0).
Metadata kept in Windows cache, refused to mount.
Failed to mount '/dev/sda6': Operation not permitted
The NTFS partition is in an unsafe state. Please resume and shutdown
Windows fully (no hibernation or fast restarting), or mount the volume
read-only with the 'ro' mount option

sudo ntfsfix /dev/sdXY

Me limitei a criar o arquivo “/etc/polkit-1/rules.d/99-udisks2.rules”, — sugerido no 4º link (abaixo), — copiar da página, e colar nele o conteúdo:

// Allow udisks2 to mount devices without authentication
polkit.addRule(function(action, subject) {
if (action.id == "org.freedesktop.udisks2.filesystem-mount-system" || action.id == "org.freedesktop.udisks2.filesystem-mount" || action.id == "org.freedesktop.udisks2.filesystem-mount-system-internal") { return polkit.Result.YES; } });