thanks all for your help! but I still didn't manage to fix this issue.

Your issue is quite rare, don't expect automated solution. Minimal knowledge about
database administration is required in this case.

that's why I'm contacting a database specialist, I'm unfortunately not very familiar with mySQL, phpMyAdmin and such...

I'll let you guys know the outcome.

Best regards

On 10/08/2018 06:36 PM, Vincent Van Houtte wrote:

Although your assessment is correct, it misses the overall picture. The question relates
to an existing installation that was merely updated. There is no reason why RC would need
to create (INSERT INTO 'users') a new user upon login.

You know nothing, John Snow ;)
@Meaulnes, the upgrade script did not fix the database structure for some reason. You have
to do this manually. Visit
https://github.com/roundcube/roundcubemail/tree/master/SQL/mysql. The files there are
named by date. You have to check all files starting from 2012080700 in order from most
recent to the oldest, until you see that the changes in the file are already in place.
Another option is to compare result of `show columns from table` command on every table
with table definitions from SQL/mysql.initial.sql file.
Your issue is quite rare, don't expect automated solution. Minimal knowledge about
database administration is required in this case.