[sv1cec]

Check your Warn.php file. Search for:

if($_GET['do']=="RemoveWarning"){

A little below that, there should be some code lines which SHOULD look like this:

if($_GET['id']=="" || !$_GET['id'] || $_GET['id']<=0){
RunError("Invalid User ID Input");
}

Make sure that it looks just like that, if it has something like $_GET['id']>1 or equal to 1, change it so that it looks exactly as above.