Error in PHP form

Issue report by Brenda Dowdell

Product

FileMaker Server

Description of the issue

When a web form which has worked perfectly in the past is accessed online, it shows an error message above a radio button input field.
What would be a possible cause for this error?

Steps to reproduce the problem

Link to the form: http://forms.danahall.org/apply/app_int.php

Exact text of any error message(s) that appear

Notice: Only variable references should be returned by reference in C:\Program Files (x86)\FileMaker\FileMaker Server\Web Publishing\publishing-engine\php\FileMaker\Implementation\LayoutImpl.php on line 37