Problem when activing zarafa Groupware services certificates

[anonymous]

When activing the services certificates of zarafa groupware i have a problem :

Some modules reported error when saving changes . More information on the logs in /var/log/ebox/

The following modules failed while saving their changes, their 
state is unknown: ca 

Then i renew the certificat of zarafa, a message appare :

root command /bin/chown root:zarafa /var/lib/ebox/tmp//ca_certificates_XULtk0 failed. Error output: /bin/chown: invalid group: `root:zarafa' Command output: . Exit value: 1 

[anonymous]

i have add a group 'zarafa' and the problem resolved.

sudo addroup zarafa

it seems a bug in zentyal-zarafa.