/usr/lib/x86_64-linux-gnu/libthumbnailer-qt.so.1.0 is in libthumbnailer-qt1.0 2.4+16.04.20160321-0ubuntu1.
This file is owned by root:root, with mode 0o777.
It is a symlink to /usr/lib/x86_64-linux-gnu/libthumbnailer-qt.so.1.0.0