WordPress Designers Stops Working due Incomplete Widget Settings

[deltaray]

I had a theme since wordpress 4 installed, and in some of the recent updates the WordPress Designer Mode was broken (Stops loading with Javascript error).

I finally found the rootcause which is array missing array settings for 2 widget zones in the widget theme config entry.

This was the entry I am talking about:
a:9:{s:19:"wp_inactive_widgets";N;s:23:"himalayas_right_sidebar";a:0:{}s:22:"himalayas_left_sidebar";a:0:{}s:28:"himalayas_front_page_section";a:0:{}s:32:"himalayas_error_404_page_sidebar";a:0:{}s:28:"himalayas_footer_sidebar_one";a:0:{}s:28:"himalayas_footer_sidebar_two";i:8409;s:30:"himalayas_footer_sidebar_three";i:8401;s:13:"array_version";i:3;}

For two zones, the array entry is missng: a:0:{}

I corrected the entry manually in the database and the problem was fixed for me:
a:9:{s:19:"wp_inactive_widgets";N;s:23:"himalayas_right_sidebar";a:0:{}s:22:"himalayas_left_sidebar";a:0:{}s:28:"himalayas_front_page_section";a:0:{}s:32:"himalayas_error_404_page_sidebar";a:0:{}s:28:"himalayas_footer_sidebar_one";a:0:{}s:28:"himalayas_footer_sidebar_two";a:0:{}i:8409;s:30:"himalayas_footer_sidebar_three";a:0:{};i:8401;s:13:"array_version";i:3;}

However there are certain areas where the existence of this Array is not checked causing unexpected errors.

[SergeyBiryukov]

Hi there, welcome to WordPress Trac! Thanks for the report.

Just noting that this seems related to #55121.