Akonadi don't start - Failed to remove Unix socket / runtime connection config file

[wired2051]

Meanwhile I made some cold-runs in VirtualBox (guest: Kubuntu 16.10, Kontact and Akonadi works fine). It works, if I do sudo apt purge akonadi-server (Akonadi was not running):

the following packages will be removed:                                                                                                                                                                     
accountwizard* akonadi-server* akonadiconsole* akregator* kaddressbook* kdepim-runtime* kjots* kmail* knotes* kontact* korganizer*                                                                      
0 updated, 0 re-installed, 11 to be removed and 105 not updated.

After sudo apt install akonadi-server and sudo apt install kontact all works fine - in the VM. No I tried it in the host, Kubuntu 16.04 (Kontact and Akonadi not working fine). After sudo apt purge akonadi-server I get this:

the following packages will be removed:
accountwizard* akonadi-server* akonadiconsole* akregator* kaddressbook* kdepim-runtime* knotes* kontact* korganizer*
0 updated, 0 re-installed, 9 to be removed and 0 not updated.

Why will kmail* not be removed? Kmail is installed (says also Muon)! I'm very anxious now.

[wired2051]

Finally I reseted Akonadi:

First I stopped Akonadi with akonadictl stop then I used Dolphin to delete / rename the folders ~/.local/share/akonadi/ and ~/.config/akonadi/ and to delete / moved the files ~/.config/akonadi*.

After that, I started Kontact - and it works!

At the end I configured my Ressourcen in KAddressBook and KOrganizer again. In Kmail I had to configure the mail-accesses, the mail-identities still existed.

Problem solved.