ERROR 256: DB connection error in PGV_DB::createInstance(): SQLSTATE[HY000] [2002] No such file or directory

Fatal error: DB connection error in PGV_DB::createInstance(): SQLSTATE[HY000] [2002] No such file or directory in /home/s04d65b4/public_html/gendb/includes/classes/class_pgv_db.php on line 405