John Blackbourn – @johnbillion

Member Since: December 7th, 2005
Location: Tonbridge, UK; and Torino, Italy
Website: johnblackbourn.com
Job Title: Senior WordPress Engineer
Employer: Human Made Ltd
Find me on:

Bio

I’m one of the team of WordPress core developers. I was the release lead for WordPress 4.1. I work as an engineer at Human Made.

Previously I’ve worked at Code For The People and WordPress.com VIP.

Contributions Sponsored

John Blackbourn contributes 8 hours per week to the following teams: CLI, Core, Documentation.

Contribution History

Accessibility Contributor
Accessibility Contributor
bbPress Contributor
bbPress Contributor
BuddyPress Contributor
BuddyPress Contributor
Core Contributor
Core Contributor
Core Team
Core Team
Documentation Contributor
Documentation Contributor
Meetup Organizer
Meetup Organizer
Meta Contributor
Meta Contributor
Translation Contributor
Translation Contributor
WordCamp Organizer
WordCamp Organizer
WordCamp Speaker
WordCamp Speaker
Plugin Developer
Plugin Developer

Activity
Plugins
Favorites

Posted a reply to Not switching at all, on the site WordPress.org Forums:
Ah yes this plugin has been mentioned in years gone past. The issue is that…

1 day ago
Closed ticket #38675, in Core Trac:
Add user language chooser to wp-signup.php

2 days ago
Posted a reply to Not switching at all, on the site WordPress.org Forums:
This may happen if you have particularly aggressive caching in place on your site, or…

2 days ago
Posted a reply to External object cache not in use, on the site WordPress.org Forums:
This means that you don't have an object cache in use. You may wish to…

3 days ago
Closed ticket #49497, in Core Trac:
imagick, is not installed, or has been disabled

5 days ago
Posted a reply to No further cron jobs in one of my sites, on the site WordPress.org Forums:
This means there's a problem on your site that is preventing your WP-Cron events from…

6 days ago
Posted a reply to Externe object-cache niet in gebruik The APCu extension for PHP is installed bu, on the site WordPress.org Forums:
Correct, it checks for several extensions: https://github.com/johnbillion/query-monitor/blob/develop/collectors/cache.php#L80-L83

1 week ago
Posted a reply to cron-job stopped working: error 404, on the site WordPress.org Forums:
It sounds like wp-cron.php got deleted. You'll need to reinstall WordPress. This isn't anything to…

1 week ago
Posted a reply to Externe object-cache niet in gebruik The APCu extension for PHP is installed bu, on the site WordPress.org Forums:
In order for your WordPress site to use APCu for its object cache, you need…

1 week ago
Closed ticket #49472, in Core Trac:
feature request: make the logout a separate page

1 week ago
Closed ticket #30343, in Core Trac:
Hello Dolly borks "Upload Plugin" and "Upload Theme" on small screens.

2 weeks ago
Posted a reply to hooks names with no associated actions, on the site WordPress.org Forums:
Yeah the majority of the time these are events left over by old plugins. The…

2 weeks ago
Posted a reply to WP-Cron spawning is disabled, on the site WordPress.org Forums:
You'll need to contact your host about this.

2 weeks ago
Posted a reply to Custom Cron Schedule Stops Running, on the site WordPress.org Forums:
Sorry you're having a problem! WP Crontrol doesn't handle running cron events, so your best…

2 weeks ago
Posted a reply to Error 502, on the site WordPress.org Forums:
https://wordpress.org/support/topic/502-gateway/

2 weeks ago
Posted a reply to Get cart should not be called before the wp_loaded action, on the site WordPress.org Forums:
Thanks for the report. Do you have the complete error message to show me, including…

2 weeks ago
Posted a reply to Redirects to WordPress login Page, on the site WordPress.org Forums:
I'm glad you find it useful! It sounds like there might be another plugin on…

2 weeks ago
Closed ticket #48443, in Core Trac:
Pass the user object to the post_locked_dialog action

3 weeks ago
Committed [47206] to Core Trac:
Posts, Post Types: Add a parameter to the `post_locked_dialog` action ...

3 weeks ago
Closed ticket #43345, in Core Trac:
term_exists() may return 0 which is not a text-documented return type

3 weeks ago
Committed [47205] to Core Trac:
Taxonomy: Clarify the docs for the return values of the ...

3 weeks ago
Closed ticket #48503, in Core Trac:
Docblock: WP_Dependency::add_data() results in 404

3 weeks ago
Committed [47204] to Core Trac:
Script Loader: Fix a docblock so it points to the correct page on the ...

3 weeks ago
Posted a reply to Switch back link isn’t displaying when Jetpack plugin activated, on the site WordPress.org Forums:
Fixed. Thanks for the reports.

3 weeks ago
Committed [2240208] to Plugins Trac:
Tagging 1.5.4

3 weeks ago
Committed [2240207] to Plugins Trac:
Committing 1.5.4 to trunk

3 weeks ago
Posted a reply to Switch back link isn’t displaying when Jetpack plugin activated, on the site WordPress.org Forums:
Yes I'm working on a fix here: https://github.com/johnbillion/user-switching/pull/49 I should be able to release a…

3 weeks ago
Created a topic, Attribution, on the site WordPress.org Forums:
Hi. The majority of this plugin's core functionality …

3 weeks ago
Posted a reply to Log info is not shown inside add_action function callback, on the site WordPress.org Forums:
Are you sure your code is being called before the graphql_register_types action fires? The qm/*…

3 weeks ago
Posted a reply to Add User Switch Back to Custom Menu, on the site WordPress.org Forums:
You can construct a Switch Back URL in PHP and display it on the page…

3 weeks ago
Posted a reply to PHP error, on the site WordPress.org Forums:
It looks from the error that the sg-cachepress plugin might be at fault. I would…

3 weeks ago
Posted a reply to WP Control plugin issues Next Run continues with Now, on the site WordPress.org Forums:
This means your WP-Cron events aren't firing for some reason. You should contact your host…

4 weeks ago
Posted a reply to Switch back link isn’t displaying when Jetpack plugin activated, on the site WordPress.org Forums:
Jetpack could either be sending output before headers are sent, or it could be triggering…

4 weeks ago
Posted a reply to Switch back link isn’t displaying when Jetpack plugin activated, on the site WordPress.org Forums:
That's strange. I just tried this out locally but couldn't see a problem with Jetpack…

4 weeks ago
Posted a reply to User switch back not working, on the site WordPress.org Forums:
Does the switch back link show up if you manually navigate to wp-login.php after switching?…

4 weeks ago
Wrote a comment on the post Lazy-Loading Images in WordPress Core, on the site Make WordPress Core:
A question was raised in #44427 about enabling lazy loading by default for all images,…

4 weeks ago
Posted a reply to Memory Limit message unclear to me, on the site WordPress.org Forums:
Thanks for the message. This does indeed mean that some code somewhere during runtime has…

1 month ago
Posted a reply to Changed contributor to supercleanse, on the site WordPress.org Forums:
I honestly thought that this plugin had been taken over by a spammer now that…

1 month ago
Posted a reply to Accidentally deleted a cron, on the site WordPress.org Forums:
Sorry to hear that. No there isn't an undo function. You might be able to…

1 month ago
Posted a reply to Ajax Warning in the admin bar, on the site WordPress.org Forums:
You'll need to check out your browser developer console to see the errors (there should…

1 month ago
Posted a reply to Disable plugin & hold settings ?, on the site WordPress.org Forums:
Looks like I forgot to follow up with this. Yes if you've changed the schedule…

1 month ago
Wrote a comment on the post Release Model Working Group – Kickoff, January 29, 2020, on the site Make WordPress Core:
Not directly, but the aim of the group is to find out what the project…

1 month ago
Posted a reply to Undefined Constant USER_SWITCHING_OLDUSER_COOKIE, on the site WordPress.org Forums:
Are you calling any of User Switching's functions on your site? For example user_switching_get_olduser_cookie() or…

1 month ago
Posted a reply to How can I modify a cron task already rcreated thanks to wp control?, on the site WordPress.org Forums:
Does the cron event that you want to edit show up on this screen? Did…

1 month ago
Posted a reply to PHP Recoverable fatal error in debug.log, on the site WordPress.org Forums:
What's the error message? Which version of PHP are you using? For PHP > 7…

1 month ago
Posted a reply to How can I modify a cron task already rcreated thanks to wp control?, on the site WordPress.org Forums:
Yes, click the Edit button next to the cron event on the Tools -> Cron…

1 month ago
Posted a reply to Plugin could not be activated because it triggered a fatal error, on the site WordPress.org Forums:
Can you try deleting the plugin entirely and reinstalling it? That method no longer exists.

1 month ago
Posted a reply to Unwanted warning notices, on the site WordPress.org Forums:
I'm not sure. The fresh keyword isn't in Query Monitor so this looks like a…

1 month ago
Joined the organizing team for WordCamp Europe 2020

1 month ago
Posted a reply to Error message: Uncaught Error: [] operator not supported for strings in, on the site WordPress.org Forums:
You'll need to contact the author of the theme about this error and send them…

2 months ago