Hi,
I’ve been running MiaB for more than two years on the same server and everything worked great. The server is hosted with DO. Given that I was about to run out of storage space I made an upgrade to the server, updated the OS and decided to update MiaB.
All the steps went flawlessly except for this error
Turned off maintenance mode
Reset log level
Start migration of all known users ...
1 [============================]
[InvalidArgumentException]
User <*@*> in unknown.
dav:migrate-calendars [<user>]
Start birthday calendar sync for all users ...
1 [============================]
Upgrading to ownCloud version 9.1.4
ownCloud or one of the apps require upgrade - only a limited number of commands are available
You may use your browser or the occ upgrade command to do the upgrade
The email worked via other clients [iOS, Thunderbird] but when I wanted to log into Roundcube I got a DB error. Visiting the logs with tail /var/log/roundcubemail/errors I saw
[07-Apr-2017 01:39:26 +0300]: <3mc7r9lk> DB Error: [1] no such table: carddav_addressbooks (SQL Query: SELECT id FROM carddav_addressbooks WHERE user_id='11' AND active=1) in /usr/local/lib/roundcubemail/program/lib/Roundcube/rcube_db.php on line 539 (GET /mail/)
[07-Apr-2017 01:39:26 +0300]: <3mc7r9lk> DB Error: [1] no such table: carddav_addressbooks (GET /mail/)
[07-Apr-2017 01:39:31 +0300]: <3mc7r9lk> DB Error: [1] no such table: carddav_addressbooks (SQL Query: SELECT id FROM carddav_addressbooks WHERE user_id='11' AND active=1) in /usr/local/lib/roundcubemail/program/lib/Roundcube/rcube_db.php on line 539 (GET /mail/)
[07-Apr-2017 01:39:31 +0300]: <3mc7r9lk> DB Error: [1] no such table: carddav_addressbooks (GET /mail/)
[07-Apr-2017 01:41:19 +0300]: <3mc7r9lk> DB Error: [1] no such table: carddav_addressbooks (SQL Query: SELECT id FROM carddav_addressbooks WHERE user_id='11' AND active=1) in /usr/local/lib/roundcubemail/program/lib/Roundcube/rcube_db.php on line 539 (GET /mail/)
[07-Apr-2017 01:41:19 +0300]: <3mc7r9lk> DB Error: [1] no such table: carddav_addressbooks (GET /mail/)
[07-Apr-2017 01:41:21 +0300]: <3mc7r9lk> DB Error: [1] no such table: carddav_addressbooks (SQL Query: SELECT id FROM carddav_addressbooks WHERE user_id='11' AND active=1) in /usr/local/lib/roundcubemail/program/lib/Roundcube/rcube_db.php on line 539 (GET /mail/)
[07-Apr-2017 01:41:21 +0300]: <3mc7r9lk> DB Error: [1] no such table: carddav_addressbooks (GET /mail/)
[07-Apr-2017 01:50:37 +0300]: <3mc7r9lk> DB Error: [1] no such table: carddav_addressbooks (SQL Query: SELECT id FROM carddav_addressbooks WHERE user_id='11' AND active=1) in /usr/local/lib/roundcubemail/program/lib/Roundcube/rcube_db.php on line 539 (GET /mail/)
[07-Apr-2017 01:50:37 +0300]: <3mc7r9lk> DB Error: [1] no such table: carddav_addressbooks (GET /mail/)
With a little bit of googling I found you can disable carddav with
nano /usr/local/lib/roundcubemail/config/config.inc.php
and editing the line
$config['plugins'] = array('html5_notifier', 'archive', 'zipdownload', 'password', 'managesieve', 'jqueryui', 'vacation_sieve', 'persistent_login', 'carddav');
by removing the last item in the plugins array.
I don’t mind disabling that plugin, but maybe this info will help out someone or it could get fixed in future releases.
Have a great one! 
PS: the issue seems to arise from the necessary DBs not being created.