/usr/share/doc/kde-window-manager-active-gles/changelog.Debian.gz is in kde-window-manager-active-gles 4:4.8.2a-0ubuntu4.
This file is owned by root:root, with mode 0o777.
It is a symlink to /usr/share/doc/kde-window-manager-active-gles/../libkdecorations4/changelog.Debian.gz