Reinstalled RoundCube and Now Get a 500 error

Symptoms

After reinstalling RoundCube, you may experience a 500 error when accessing RoundCube via Webmail.

Description 

When reinstalling RoundCube, some configuration files may no longer be present, resulting in the 500 error.

Workaround

1. Access the server's command line as the 'root' user via SSH or "Terminal" in WHM.
2. Update the Roundcube database schema.
   • MySQL Roundcube database

     /usr/local/cpanel/bin/update-roundcube-db --foreground

   • SQLite Roundcube database

     /usr/local/cpanel/bin/update-roundcube-sqlite-db --foreground

Additional resources

How to Rebuild the Roundcube Database

How do I convert Roundcube from MySQL to SQLite?