The 'Help' button does nothing when clicked in any System preferences screen. This button is next to 'Default' and 'Reset' buttons. Fresh install of KDE NEON User edition. Maybe related to [bug #380081](https://bugs.kde.org/show_bug.cgi?id=380081)
Is khelpcenter installed?
(In reply to David Edmundson from comment #1) > Is khelpcenter installed? Thanks a lot David. Just installed it (sorry for not trying before, as suggested in #3800081), and now the 'Help' button opens the KDE Help Center, so the problem is solved. In my opinion, a new problem arises: Shouldn't be 'kdehelpcenter' installed by default in KDE Neon? Shall I open a new bug report or should we leave this open?
*** This bug has been marked as a duplicate of bug 380081 ***