This topic shows how to fix the issue

Hello, after login to zAdmin and clicking "Launch Webmail" i got following error:

Unable to connect to the database!
Please contact your server-administrator.
What is the cause and fix? in /root/passwords.txt i found "MySQL Root Password: ******"

So i did this command from linux command line: "mysqlcheck -u root -p -r roundcube"
After entering password mentioned above, i got: "mysqlcheck: Got error: 1049: Unknown database 'roundcube' when selecting the database"

So what is RoundCube mysql name and where i can update its mysql credentials?

mysql -u root -p
then command "show databases;"
"| zpanel_roundcube |"

Now what are ROundcube mysql config file to connect into mysql?

find / -type f -name ""

So i editted file /etc/zpanel/configs/roundcube/ because i seen password mentioned there is somehow incomplete,
Lookup line: "$rcmail_config['db_dsnw']"

FIXED: after this change and saving that file, i see Round Cube login screen !

The password? zAdmin / Mail / Mailboxes