Okay I've found a workaround for the issue :
0/ Backup your user account !!!
1/ Stop Akonadi, Kontact, and the MySQL process launched by Akonadi.
2/ rm -rf ~/.config/akonadi
3/ rm -rf ~/.local/share/akonadi
4/ Restart Kontact
5/ Reconfigure the apps so that they correctly point to the folders and files where the data is.
Anyway this is not suitable in a production environment, and the fix should be done. I point that the error occured after an upgrade from Oneiric.
Okay I've found a workaround for the issue : share/akonadi
0/ Backup your user account !!!
1/ Stop Akonadi, Kontact, and the MySQL process launched by Akonadi.
2/ rm -rf ~/.config/akonadi
3/ rm -rf ~/.local/
4/ Restart Kontact
5/ Reconfigure the apps so that they correctly point to the folders and files where the data is.
Anyway this is not suitable in a production environment, and the fix should be done. I point that the error occured after an upgrade from Oneiric.