Reasons:

Database Connection Information is Incorrect: This error may be received if the information required to access Roundcube's database, such as username, password, or database name, is incorrect.
The DatabDatabase Connection Information is Incorrect: This error may be received if the information required to access Roundcube's database, such as username, password, or database name, is incorrect.
The Database Server is Inaccessible: There may be a problem accessing the database server on your server. This may occur in situations such as when the server is offline or the network connection is disconnected.
Roundcube Installation Error: This error may occur if Roundcube is not installed properly or if there is an error during installation.
Firewalls or Permissions: Firewalls or permissions settings may prevent Roundcube from accessing the database.
Solution MethodsFirewalls or Permissions: Firewalls or permissions settings may prevent Roundcube from accessing the database.
Solution Methods:

Check the Database Connection Information: In the Roundcube's config file (config/config.ialls or Permissions: Firewalls or permissions settings may prevent Roundcube from accessing the database.
Solution Methods:

Check the Database Connection Information: In the Roundcube's config file (config/config.inc.php) check the specified database connection information. Make sure that the username, password, and database name are correct.
Check the Database Server: Make sure the database server on your server is running and accessible. You can check this with your server provider or system administrator.
Update or Reinstall the Roundcube: Check if the Roundcube is up to date. If it is not up to date, try updating it. Also, you can fix the installation error by reinstalling Roundcube.Update or Reinstall the Roundcube: Check if the Roundcube is up to date. If it is not up to date, try updating it. Also, you can fix the installation error by reinstalling RouUpdate or Reinstall the Roundcube: Check if the Roundcube is up to da it is not up to date, try updating it. Also, you can fix the installation error by reinstalling Roundcube.
Check Firewall and Permissions: Make sure that the firewalls on your server are not blocking Roundcube's access to the database and that the necessary permissions are granted.
Solution via Command: You can update Roundcube by connecting to your server via SSH and running the following command:

/usr/local/cpanel/bin/update-roundcube –force
Any of the above methods should generally be sufficient to resolve the "Database Connection Failed" error. However, if the issue persists, it is recommended that you contact your system administrator or server providerAny of the above methods should generally be sufficient to resolve the "Database Connection Failed" error. However, if the issue persists, it is recommended that you contact your system administrator or server provider.

Roundcube #DATABASE Connection #cPanel #SERVER Calls #DATABASE PROBLEMS #WebMail #SERVER MANAGEMENT #Email Services #SSH Commands #We