Only variables can be passed by reference in

Fatal error: Only variables can be passed by reference

In this line:

foreach ($arFields["PROPERTY_VALUES"]["72"] as $key=>$moreimg)
{
    CWaterMark::PostWaterMark($moreimg["VALUE"]["tmp_name"]);
}

The array looks like

[78] => Array
                (
                    [n0] => Array
                        (
                            [VALUE] => Array
                                (
                                    [name] => c8b79ce78f_154881.jpg
                                    [type] => image/jpeg
                                    [tmp_name] => /var/www/4.ru/data/mod-tmp/php0B6qCw
                                    [error] => 0
                                    [size] => 163406
                                )
                            [DESCRIPTION] => 
                        )
                    [n1] => Array
                        (
                            [VALUE] => Array
                                (
                                    [name] => erheben2.jpg
                                    [type] => image/jpeg
                                    [tmp_name] => /var/www/4.ru/data/mod-tmp/phpkZmLY3
                                    [error] => 0
                                    [size] => 225747
                                )
                            [DESCRIPTION] => 
                        )

Answer 1, authority 100%

Found on the Internet:

CWaterMark::PostWaterMark(&$arFields["PROPERTY_VALUES"]["72"][$key]['VALUE']['tmp_name']);

Notice the &