I have installed Leap 42.1 by selecting KDE Desktop as primary desktop and selected GNOME desktop in Software selection and now KDE desktop is working fine but when switched to GNOME during logon it just hangs. I have to kill Gnome service process using SSH from another PC.
Is it a problem to have dual desktops KDE & GNOME on the same installation ?
But I checked, and an update to fix this has indeed been released for Leap 42.1, last November already shortly after the release of Leap 42.1.
So please update your system, if in doubt please post your repo list to see whether you have the update repo in your list and it is enabled.