There are very specific reasons that we do not want the Pro theme to know that Gravity Forms is enabled and have defined X_GRAVITY_FORMS_IS_ACTIVE as false. We do this, as is best practice, wrapped in an if statement to make sure that it is not already defined.
However, in the file framework/functions/plugins/setup.php
(line 25 in v2.3.6), it is again defined and a PHP notice is thrown:
( ! ) Notice: Constant X_GRAVITY_FORMS_IS_ACTIVE already defined in …/wp-content/themes/pro/framework/functions/plugins/setup.php on line 25
Albeit just a notice, I would definitely consider this a bug and poor coding practices.
In the meantime, I have used notice suppression on that line, but this is a sloppy workaround and will not play well when updates to the theme are made.
Please advise as to how this should be handled.