Support » Plugin: Classic Editor Addon » WordPress v5.3 Errors

  • Resolved TheViv


    Tried to update from v5.2.4 to 5.3 on three different sites using this plugin.

    Warning: Declaration of WPDI_Plugin_Installer_Skin::feedback($string) should be compatible with WP_Upgrader_Skin::feedback($string, …$args) in /wp-content/plugins/classic-editor-addon/vendor/afragen/wp-dependency-installer/wp-dependency-installer.php on line 526

    Warning: Cannot modify header information – headers already sent by (output started at /wp-content/plugins/classic-editor-addon/vendor/afragen/wp-dependency-installer/wp-dependency-installer.php:526) in /wp-admin/includes/misc.php on line 1252

    Warning: Cannot modify header information – headers already sent by (output started at wp-content/plugins/classic-editor-addon/vendor/afragen/wp-dependency-installer/wp-dependency-installer.php:526) in /wp-admin/admin-header.php on line 9

Viewing 15 replies - 1 through 15 (of 15 total)
  • Just verified it’s the Classic Editor Addon and not the Classic Editor which is causing the errors. I hope you can fix this. I am using version 2.5.0.

    Thank you.

    Just discovered one of my sites using Classic Editor is down – there may be many more.

    I had never heard of this plugin until I logged into the cPanel to remove the Classic Editor plugin and try to get the site live again — only to find there was no way to disable it!

    There was a “second” Classic Editor plugin – this one – and I did not yet know it had been injected into my site with the Update to WP 5.3 I did a few moments ago.

    What a nightmare – I manage many sites and they may all be affected.

    I see you are not the developers of the original plugin – I wish I had’ve known a new plugin would be added to my site which rendered a plugin of my choice turned “off”.Please advise when a solution will be provided.

    Please also advise how to now access the Classic Editor plugin which was working fantastically well until now.

    PS – I temporarily fixed the problem by removing both plugins via cPanel, while I investigate further.

    I had the exact same problem.

    My sites are hosted at Siteground.

    After working through things with them, they simply rolled back PHP to 5.6 on my site and the problem was fixed.

    Of course, now there was a nag on the WP Control Panel that I had an outdated version of PHP.

    I upgraded to 7.1 and the problem with the Classic Editor Addon re-appeared.

    So it appears that somehow upgrading to WordPress 5.3 causes the Classic Editor Addon to stop being compatible with PHP 7.1

    That is outside my level of knowledge, but I want to throw that in there to help diagnose.

    For now I am just going to disable the Classic Editor Addon plugin on my sites.

    But I do like having it, so I hope this is able to be fixed.

    Thanks for the plugin.

    Confirming the Classic Editor plugin is working again now I’ve deleted the “Addon” plugin via cpanel. My site is ‘live’ again and I can login.

    To the plugin author(s)

    From a developer/tech standpoint, this appears to be a change to /wp-admin/includes/class-wp-upgrader-skin.php. The feedback function now has a spread operator as a 2nd parameter. See for more info on spread operators in WP 5.3.

    A possible fix is to update the WP Dependency Installer class as follows:
    /vendor/afragen/wp-dependency-installer/wp-dependency-installer.php line 530

    public function feedback( $string ) {}

    public function feedback( $string, ...$args ) {}

    I changed the code on my dev site and the warning went away. However I have not fully tested to see what the impact of this change is.

    As a followup, it looks like this change has already been added to the WP Dependency Installer Github repo and just needs to be ported into the plugin.



    Same issue as above. Using Filezilla I removed the plugin ‘Classic Editor Addon’. Now able to access my site. All seems ok.

    I updated to WP v 5.3 on another site hosted elsewhere that is using PHP 7.1 and it was fine with the plugin.

    The other three sites are all set at PHP 7.0. Should this be changed?

    Same issue as the OP on my end.

    Plugin Author Pieter


    Thanks for the reports and apologies for the inconvenience. We will roll out a new compatible version with the updated dependency installer as referred to by @gr-web-guy

    Thanks Pieter! @senlin

    Let us know when that is done and I’ll go back in and turn those plugins back on in my various sites. 🙂

    I do like the plugin.

    Plugin Author Pieter


    @nadinenb @octotoot @healthy-lawn-dude @gr-web-guy @webgirlie

    We have just released version 2.6.0 which solves the issue. Thanks for reporting and for your patience and apologies for any inconvenience caused by this!

    Thank you! 🙂

    Plugin Author Pieter


    My pleasure Jon @thirstyjon and glad to hear that you’re turning the plugin back on after this “debacle” 😉

Viewing 15 replies - 1 through 15 (of 15 total)
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