/usr/lib/x86_64-linux-gnu/libukui-panel-applet-4.so is in libukui-panel-applet-dev 1.1.3-0ubuntu1.
This file is owned by root:root, with mode 0o777.
It is a symlink to /usr/lib/x86_64-linux-gnu/libukui-panel-applet-4.so.1.0.1