Comment # 7 on bug 1042448 from Fabian Vogt

(In reply to Chris Ward from comment #6)
> I'm trying to start kde 5. In my attempts to figure what is going wrong, I
> have also attempted to start kde 4; I get the same problem (mouse cursor
> works, but no kde session).
> 
> Would it help to post some output from 'journalctl' ?

It may, ~/.xsession-errors-:0 would be helpful as well (after launching with
sddm).