It's, as desga2 says, a wrong kplugin version. Look at the folder, to see it. Don't forget also that in kplugins, there is sometimes kplugins added by extension.
Rename it, just to find the which causes the problem.
Mozilla/5.0 (x11; U; Linux x86_64; fr-FR; rv:38.0) Gecko/20100101 Ubuntu/12.04 K-Meleon/76.0
Mail : alain [dot] aupeix [at] wanadoo [dot] fr
Ubuntu 12.04 - Gramps 3.4.9 - Harbour 3.2.0 - Hwgui 2.20-3 - K-Meleon 76.0 rc