/usr/lib/x86_64-linux-gnu/libArcus.so.3 is in libarcus3 3.1.0-1ubuntu1.
This file is owned by root:root, with mode 0o777.
It is a symlink to /usr/lib/x86_64-linux-gnu/libArcus.so.1.1.0
/usr/lib/x86_64-linux-gnu/libArcus.so.1.1.0