Frustratingly the GoogleAppLauncher can't replicate this and the error only occurs on production. Essentially I have a form submitting json to mailchimp. It is erroring at the javascript and I can't work out why. You can see the 500 error if you try to submit the form - https://v-sons.appspot.com/our-underwear/#subscribe
On the server looks to be a Call to undefined function add_theme_support()
however the console tells a different story (I don't understand whether the two relate / not).
In my console, the jQuery error references:
xhr.send( ( s.hasContent && s.data ) || null );
However digging deeper it looks to be a problem with the $.ajax
anonymous function of this code block that's being submitted:
jQuery.ajax({
url: action,
type: 'POST',
data: $stickyForm.serialize(),
success: function(data)
{
window.location.hash = 'nearly';
$('#modalOverlay').addClass('nearly').fadeIn();
$('#stickyEmail').val("");
$('#nickName').focus();
}
});
I've tried to cover as much as I can with this, because to be honest I'm not sure where the problem really lies. It'd be really great to get an answer / some help though because I've been bashing keys for hours trying to work this out. The main problem is this isn't a problem on my local server, and I don't know from what end to attack the problem.
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Update: It has just occurred to me that this error might have been created by issuing the other fix I used on this other related question I asked the community - 500 Error when Migrating Wordpress to Google Cloud