Interesting error and not a useful intervention by Klipper <lol> Check
the setting in Klipper to see if any actions have been added but in
the end you may need to purge and then re-install using a package
manager such as Muon or Synaptic. Note the Muon Software Center will
not be able to do this, use Muon Package Manager to select Klipper and
then select 'Mark for purge' to remove all settings etc before putting
it back in again.

Then again - have you installed any other clipboard tool ? If so then
that may be the problem so purge that one instead and see if that
fixes this annoying glitch.