/usr/lib/x86_64-linux-gnu/libXfixes.so.3 is in libxfixes3 1:5.0.1-2+deb8u1.
This file is owned by root:root, with mode 0o777.
It is a symlink to /usr/lib/x86_64-linux-gnu/libXfixes.so.3.1.0
/usr/lib/x86_64-linux-gnu/libXfixes.so.3.1.0