Comment 5 for bug 1781392

lxqt-common is deprecated in upstream, debian and ubuntu - and anywhere else. It will be removed from debian testing soon and from sid after the upcoming debian release - please see also the respective launchpad bug in lxqt-common. In short: lxqt is not co-installable with the current version of LXQt.

All files that was former in lxqt-common are moved to the packages where they belong to. If you run a pure ubuntu installation with LXQt as only desktop environment you have some sane choices:
* fix 60x11-common-xdg... (just add /usr/share to the config_dirs) or delete this file - or maybe better copy that file to 61x11.. and leave only the fixed path in
* update right now to cosmic
* backport the patch from cosmic to your package