/usr/lib/x86_64-linux-gnu/libcinnamon-menu-3.so.0 is in libcinnamon-menu-3-0 3.6.0-1.
This file is owned by root:root, with mode 0o777.
It is a symlink to /usr/lib/x86_64-linux-gnu/libcinnamon-menu-3.so.0.0.1
/usr/lib/x86_64-linux-gnu/libcinnamon-menu-3.so.0.0.1