$this->default_headers; is not set as an array

[grapplerulrich]

I get this error in the customizer(wp-admin/customize.php)

Warning: Invalid argument supplied for foreach() in /wp-admin/custom-header.php on line 1248

Warning: array_merge(): Argument #2 is not an array in /wp-admin/custom-header.php on line 1268

I came across this bug in ​Responsive and was able to replicate it in TwentyTwelve with a minor code change.

This error arrises when a default image is set for add_theme_support( 'custom-header' );

Change 'default-image' => '', to 'default-image' => get_template_directory_uri() . '/inc/default-image.png', in /wp-content/themes/twentytwelve/inc/custom-header.php line 26 to replicate.

[grapplerulrich]

This was introduced with #21785

[ocean90]

Duplicate of #27850.

[rocketero]

I also saw those lines errors like Warning: Invalid argument supplied for foreach() in /wp-admin/custom-header.php on line 1248

there were several of them and they disappeared very quick and then it shows the responsive page.

Also I don't see where to edit those 3 widgets at the bottom of the page or the content with the monkey image.

[SergeyBiryukov]

It's still a duplicate of #27850.