4.4.0-96.119) is not available, but a newer one is (4.4.0-142.168). We redirected you there.
/usr/lib/x86_64-linux-gnu/libmrpt-gui.so.1.4 is in libmrpt-gui1.4 1:1.4.0-7.
This file is owned by root:root, with mode 0o777.
It is a symlink to /usr/lib/x86_64-linux-gnu/libmrpt-gui.so.1.4.0