transport error – HTTP status code was not 200 (403)

Could you post your site URL here, so I can have a look?

If you want it to remain private, you can also contact us via this contact form:
https://jetpack.com/contact-support/

Could you also post a list of the other plugins you currently use on that site? If you use other comment / anti-spam / security plugins, it might be worth trying to deactivate them for a few minutes, to see if one of them conflicts with Jetpack’s Comments module.
It would also be good to try to deactivate Jetpack’s Comments module (under Jetpack > Settings > Engagement), and see if the problem remains when you use WordPress’ core comments.

I deactivated Jetpack Comments and it worked, so left it as that, but I just tried jetpack again, and got the same error.

I deactivated both Captcha plugins (Really Simple CAPTCHA and SI CAPTCHA Anti-Spam), but this made no difference. Also deactivated iQ Block Country, Theme My Login and Registration Control.

I have reactivated Jetpack Comments, so you can see it as not working. Thanks

The site is https://www.brisbanebayside.com
Feel free to try leaving a comment at a post created for testing comments: https://www.brisbanebayside.com/testing-december-2016

The plugins in use are:
Ads by datafeedr.com
AdSense Integrator
Akismet
Another WordPress Classifieds Plugin (AWPCP)
Child Themify
Contact Form 7
Custom fields shortcode
Datafeedr Random Ads V2
Export Users Data to CSV for MS Excel
Flexi Pages Widget
Gallery Manager Lite
Google XML Sitemaps
iQ Block Country
Jetpack by WordPress.com
Link Library
List category posts
List Pages Shortcode
Manage Your Posts Only
MapPress Easy Google Maps
Max Mega Menu
Official StatCounter Plugin
Optimize Database after Deleting Revisions
Post Type Switcher
Postman SMTP
Pretty Link Lite
Really Simple CAPTCHA
Registration Control
Search & Filter
SI CAPTCHA Anti-Spam
Smart Ads
T&P Gallery Slider
Taxonomy Dropdown Widget
Theme My Login
UpdraftPlus – Backup/Restore
WP All Export
WP Easy Paypal Payment Accept
WP External Links
WP Mobile Edition
WP Simple Paypal Shopping cart
Wp-Insert
WP125

Thanks for the extra details. Those plugins would have been my first guesses as well.

Could you try to deactivate Registration Control and WP All Export as well, and let me know if it helps?

If you continue to experience issues, could you try to edit your site’s .htacess file, and see if it includes extra redirect rules that may have been added by plugins you used to have on your site?

Thanks!

After removal of the following:

Really Simple CAPTCHA
SI CAPTCHA Anti-Spam
iQ Block Country
Theme My Login
Registration Control
WP All Export

it still does not work.

I looked at htaccess and saw a lot of code in there:

367 lines of code for iThemes Security (even though not activated)
206 lines of code for All In One WP Security (even though not activated)
10 lines of code for WordPress
4 lines of code for CloudFlare (even though no longer used)

I removed the 367 lines of code for iThemes Security, and submitted a comment “Testing after iThemes Security code removed” but got: HTTP 404 error
That’s odd… Microsoft Edge can’t find this page

Then I removed the code for All In One WP Security and submitted a comment “Testing after All In One WP Security code removed”

That allowed me to submit a comment…. at last.

This made me realise that code is still in place for plugins that are not even activated.

Thanks for pointing me in the right direction.

I re-activated:

Really Simple CAPTCHA
SI CAPTCHA Anti-Spam
Theme My Login
Registration Control

and comments still work.

I checked another of my sites, (https://www.britzinoz.com/testing-comments) and just de-activated the Anti-Spam plugin, to get Jetpack comments operating on that one.