[wp-trac] [WordPress Trac] #51949: Error after switching themes on wordpress

[WordPress Trac]

#51949: Error after switching themes on wordpress
--------------------------+------------------------------
 Reporter:  pranav1326    |       Owner:  (none)
     Type:  defect (bug)  |      Status:  new
 Priority:  normal        |   Milestone:  Awaiting Review
Component:  General       |     Version:
 Severity:  critical      |  Resolution:
 Keywords:  php8          |     Focuses:
--------------------------+------------------------------
Changes (by hellofromTonya):

 * keywords:   => php8


Old description:

> When I try to switch a theme this error happens. And after this error
> whole, WordPress is not working or even opening. I have uninstalled and
> reinstalled WordPress once but the same thing happened. I searched on
> google and I find out this is because of PHP version 8.
>

> Fatal error: Uncaught ArgumentCountError: array_merge() does not accept
> unknown named parameters in C:\xampp\htdocs\wordpress\wp-
> includes\widgets.php:1265 Stack trace: #0 C:\xampp\htdocs\wordpress\wp-
> includes\widgets.php(1265): array_merge(wp_inactive_widgets: Array,
> sidebar-1: Array, footer-1: Array, footer-2: Array, footer-3: Array) #1
> C:\xampp\htdocs\wordpress\wp-includes\widgets.php(1220):
> retrieve_widgets(true) #2 C:\xampp\htdocs\wordpress\wp-includes\class-wp-
> hook.php(289): _wp_sidebars_changed('Twenty Twenty') #3
> C:\xampp\htdocs\wordpress\wp-includes\class-wp-hook.php(311):
> WP_Hook->apply_filters(NULL, Array) #4 C:\xampp\htdocs\wordpress\wp-
> includes\plugin.php(478): WP_Hook->do_action(Array) #5
> C:\xampp\htdocs\wordpress\wp-includes\theme.php(3267):
> do_action('after_switch_th...', 'Twenty Twenty', Object(WP_Theme)) #6
> C:\xampp\htdocs\wordpress\wp-includes\class-wp-hook.php(287):
> check_theme_switched('') #7 C:\xampp\htdocs\wordpress\wp-includes\class-
> wp-hook.php(311): WP_Hook->apply_filters(NULL, Array) #8
> C:\xampp\htdocs\wordpress\wp-includes\plugin.php(478):
> WP_Hook->do_action(Array) #9 C:\xampp\htdocs\wordpress\wp-
> settings.php(546): do_action('init') #10 C:\xampp\htdocs\wordpress\wp-
> config.php(90): require_once('C:\\xampp\\htdocs...') #11
> C:\xampp\htdocs\wordpress\wp-load.php(37):
> require_once('C:\\xampp\\htdocs...') #12 C:\xampp\htdocs\wordpress\wp-
> blog-header.php(13): require_once('C:\\xampp\\htdocs...') #13
> C:\xampp\htdocs\wordpress\index.php(17): require('C:\\xampp\\htdocs...')
> #14 {main} thrown in C:\xampp\htdocs\wordpress\wp-includes\widgets.php on
> line 1265
>
> There has been a critical error on your website.

New description:

 When I try to switch a theme this error happens. And after this error
 whole, WordPress is not working or even opening. I have uninstalled and
 reinstalled WordPress once but the same thing happened. I searched on
 google and I find out this is because of PHP version 8.



 {{{
 Fatal error: Uncaught ArgumentCountError: array_merge() does not accept
 unknown named parameters in C:\xampp\htdocs\wordpress\wp-
 includes\widgets.php:1265

 Stack trace:
 #0 C:\xampp\htdocs\wordpress\wp-includes\widgets.php(1265):
 array_merge(wp_inactive_widgets: Array, sidebar-1: Array, footer-1: Array,
 footer-2: Array, footer-3: Array)
 #1 C:\xampp\htdocs\wordpress\wp-includes\widgets.php(1220):
 retrieve_widgets(true)
 #2 C:\xampp\htdocs\wordpress\wp-includes\class-wp-hook.php(289):
 _wp_sidebars_changed('Twenty Twenty')
 #3 C:\xampp\htdocs\wordpress\wp-includes\class-wp-hook.php(311):
 WP_Hook->apply_filters(NULL, Array)
 #4 C:\xampp\htdocs\wordpress\wp-includes\plugin.php(478):
 WP_Hook->do_action(Array)
 #5 C:\xampp\htdocs\wordpress\wp-includes\theme.php(3267):
 do_action('after_switch_th...', 'Twenty Twenty', Object(WP_Theme))
 #6 C:\xampp\htdocs\wordpress\wp-includes\class-wp-hook.php(287):
 check_theme_switched()
 #7 C:\xampp\htdocs\wordpress\wp-includes\class-wp-hook.php(311):
 WP_Hook->apply_filters(NULL, Array)
 #8 C:\xampp\htdocs\wordpress\wp-includes\plugin.php(478):
 WP_Hook->do_action(Array)
 #9 C:\xampp\htdocs\wordpress\wp-settings.php(546): do_action('init')
 #10 C:\xampp\htdocs\wordpress\wp-config.php(90):
 require_once('C:\xampp\htdocs...')
 #11 C:\xampp\htdocs\wordpress\wp-load.php(37):
 require_once('C:\xampp\htdocs...')
 #12 C:\xampp\htdocs\wordpress\wp-blog-header.php(13):
 require_once('C:\xampp\htdocs...')
 #13 C:\xampp\htdocs\wordpress\index.php(17): require('C:\xampp\htdocs...')
 #14 {main} thrown in C:\xampp\htdocs\wordpress\wp-includes\widgets.php on
 line 1265
 }}}


 There has been a critical error on your website.

--

Comment:

 Hello @pranav1326 and Welcome to Trac!

 Thank you for reporting this issue.

 Are you running WordPress 5.6 RC4? If no, what version of WordPress is
 running on your website?

-- 
Ticket URL: <https://core.trac.wordpress.org/ticket/51949#comment:2>
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