I just upgraded to the latest version of wordpress 5.5 and my theme stopped working. The categories are no longer automatically selected when I click the button.


  • 1
    Does WordPress work with a default theme enabled (Twenty Twenty, for example)? If so, you'll need to consult your theme's official support streams.
    – Pat J
    Commented Aug 15, 2020 at 16:59
  • 4
    Try to purge your browser cache.
    – SilvR-O
    Commented Aug 18, 2020 at 8:52
  • 2
    Purging cache helped me, weird issue, never seen this before.
    – dingo_d
    Commented Aug 20, 2020 at 13:48
  • 1
    See ticket: core.trac.wordpress.org/ticket/51123
    – birgire
    Commented Sep 15, 2020 at 16:55
  • On 15/10/2020 downgrade to 5.4.2 wordpress.org/plugins/wp-downgrade Commented Oct 15, 2020 at 15:35

1 Answer 1


This is Trac ticket 51223:

commonL10n and other JS globals removed without backwards compatibility

In WordPress 5.5, the localized translations under commonL10n were replaced by wp.i18n.__ without deprecation notice or backwards compatibility. Plugins using commonL10n now have JavaScript errors introduced by updating WordPress which can break site functionality.

It was fixed in 5.5.1 by adding a compatibility layer. The best fix is to upgrade to 5.5.1.

commonL10n is still deprecated, however, and will be removed in 5.7.

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