Fatal error: Exception thrown without a stack frame in Unknown

hello.

im really interesting in your class and i make another class using Ultimate MySQL, but send me this error

"Fatal error: Exception thrown without a stack frame in Unknown on line 0"

this is the code for my class.

<?php
class recovery {

private $mssql;
private $mysql;

function __construct($mysql ,$mssql){
$this->mysql = $mysql;
$this->mssql = $mssql;

}

function crear_tablas(){
$this->mysql->Open();
$this->mysql->ThrowExceptions = true;
try{
$lista = array (
'create table if not exists `historico_digital`(
`id` int(18) not null auto_increment,
`fecha` varchar(23)not null,
`edo_valor` tinyint(1) not null,
`kf_tag` varchar(20) not null,
index(`id`),
primary key (`id`)
)type=innodb;'
,
'create table if not exists `catalogo_digital`(
`id` int(18) not null auto_increment,
`tag` varchar(20) not null,
`mensaje` varchar(128) not null default "sin mensaje",
`se` varchar(10) not null,
`0msg` varchar(32) not null default "default",
`1msg` varchar(32) not null default "default",
index(`id`),
primary key (`tag`)
)type=innodb;'

);

for ($i = 0; $i< count($lista); $i++){
$this->mysql->Query($lista[$i]);
}

}
catch(Exception $e) {
echo "Se ha producido un error u_u " . $e->getMessage();
}
$this->mysql->Close();

}
}

?>

thanks for your help.