these Openlp is installed on Kubuntu 17.10. So I do think it's actual…
Since last Sunday Olp presents pictures dark and letters in red by beamer suddenly. On the monitor everything is good. The vga cable is ok, too. Pictures opend by an other viewer on the same hardware are all good.
I do know that with this informations it can be only a start post.
Be free to ask all you want to know
He blesses you