Fatal PhpWiki Error

Fatal PhpWiki Error:

lib/WikiDB/backend/PearDB.php:54 Error: Can't connect to database: WikiDB_backend_PearDB_mysqli: fatal database error

DB Error: connect failed
( [nativecode=Connection refused] ** mysqli://cyberleo_wiki:XXXXXXXX@db/cyberleo_wiki)

Notice: "Constant PHPWIKI_BASE_URL already defined"

lib/WikiDB/backend/PearDB.php:54 Error: Can't connect to database: WikiDB_backend_PearDB_mysqli: fatal database error

DB Error: connect failed
( [nativecode=Connection refused] ** mysqli://cyberleo_wiki:XXXXXXXX@db/cyberleo_wiki)