/usr/lib/libACE_TkReactor.so is in libace-tkreactor-dev 6.0.1-3.
This file is owned by root:root, with mode 0o777.
It is a symlink to /usr/lib/libACE_TkReactor-6.0.1.so
/usr/lib/libACE_TkReactor-6.0.1.so