Potřeboval bych poradit proč mi mssql_query neustále navrací false a chybovou hlášku

"MSSQL error: Unicode data in a Unicode-only collation or ntext data cannot be sent to clients using DB-Library (such as ISQL) or ODBC version 3.7 or earlier."

$link = mssql_connect('xxxxx','skoldat','yyyy');
if(!link){
        die('Something is wrong');
}else{
        print('All is good!');
}
mssql_select_db('skoldat',$link);
$c = mssql_query('SELECT * FROM skoldat.dbo.sk_user',$link);
var_dump($c);

$version = mssql_query('SELECT @@VERSION');
$row = mssql_fetch_array($version);

echo $row[0];