This is a duplicate of bug #1235325. Please see that bug for details and note that this can be fixed for saucy because the apparmor policy is allowing the suggested path already. Ie, apparmor policy has:
/usr/lib/@{multiarch}/thumbnailer/vs-thumb ixr,
due to discussion in bug #1235325 where it is recommended that /usr/lib/$arch/thumbnailer/vs-thumb be used.
This is a duplicate of bug #1235325. Please see that bug for details and note that this can be fixed for saucy because the apparmor policy is allowing the suggested path already. Ie, apparmor policy has: lib/@{multiarch }/thumbnailer/ vs-thumb ixr,
/usr/
due to discussion in bug #1235325 where it is recommended that /usr/lib/ $arch/thumbnail er/vs-thumb be used.