Error in qtransxf programming

Does anybody know what to do with the following error on my site?

Warning: Parameter 2 to qtranxf_postsFilter() expected to be a reference, value given in?/var/www/wp-includes/class-wp-hook.php?on line?308

I really love this plugin and my whole site works on it so if anybody can let me know how to change which php file that would be great.

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