This is a direct copy of benjifisher's D8 issue #1863388: syntax error in update_manager_update_form(). The issue in D8 is revolved by moving to the new form interface, however the problem is also in D7.
The function declaration is
<?php
function update_manager_update_form($form, $form_state = array(), $context) {
?>If the second argument has a default value, then the third argument is supposed to have one, too.
I am not sure of the correct fix: give $context a default value, remove the default value from $form_state, or remove the third argument entirely (and maybe also the default value). AFAICT, $context is not referred to anywhere in the code. I did not see func_get_args() either, but maybe I overlooked something.