I get several sequential lines with this error every time I issue 'akonadictl start'.
Does anyone know why does this happen and how may I go about fixing it?

I run Plasma v5.11.5, Frameworks v5.43.0, Apps v17.12.3, and Qt v5.9.4 on a Poettering-free install.

Just for the record, facing the same issue. It is reported here: https://bugs.kde.org/show_bug.cgi?id=393280