add_action stopped working

For some reason, it seems my add_action has stopped working. I'm using both an add_filter, and an add_action in my functions.php page, and both were working beautifully last week. I've even tried reverting the site back to previous versions, but to no avail. Currently, the add_filter is still working, but I can't get any response out of the add_action.

Even if I just put a echo within the function called, I get no response to the screen.

Any help or method to debug would be greatly appreciated! (I've totally disabled the calling feature until I can get a response out of the form).

What could be the reason's this doesn't work? Or, what is the best way to debug?

functions.php

add_action("gform_after_submission_1", "post_free_meter", 10, 2);
function post_free_meter($entry, $form) {

	echo "<h1> TEST FREE METER ADD ACTION </h1>" ;

}

OK, I was able to fix this.... the trick is not to try and use the echo command within the function called from the add_action("gform_after_submission",...) -- it WONT print to the screen. So, even though my post_free_meter($entry, $form) function was being called, I was unable to diagnose the issue using an echo.

This is what made it hard to debug for me.