Desktop background etc. gone

Hi, On a 15.2 box, KDE Plasma, suddenly the background of the (two) screens, the ordering of desktop icons, and, more pityful, also all the notes on the desktop are gone. Is there any chance to get that back? Does Plasma save older sessions, like e.g. firefox does? I can't find anything related in ~/.config/plasma* files. Any ideas? Thanks in advance, regards, Jogchum