This ("extension not found") means that your PHP installation does not provide MySQL (or whatever database type you configured) support.

Thomas

P C wrote:

Using Roundcube v0.1-beta, MySql 5.0, PHP 5.1.2, - all windows versions. After installing, I got this error in the log... [27-Feb-2006 13:47:45 -0500] DB Error: DB Error: extension not found in C:\inetpub\WebMail\program\include\rcube_db.inc on line 97 [27-Feb-2006 13:47:45] PHP Fatal error: Call to undefined method DB_Error::query() in C:\inetpub\WebMail\program\include\rcube_db.inc on line 213