Support » Plugin: Classic Editor » js error Edit Post page Broken After Update to WP 5.6

Viewing 8 replies - 1 through 8 (of 8 total)
  • Plugin Author Andrew Ozz


    The Deprecated TinyMCE API call message in the browser tools means you have a WP plugin that is loading some very very old TinyMCE script. It still (probably) works because of the back-compat code there, but may cause other problems and may stop working in the future.

    However that shouldn’t cause the editor to stop working. It is isolated to that old script.

    Are there any other errors shown in the browser tools? Also, could you try reloading the page couple of times while holding down Shift and see if that changes anything.

    • This reply was modified 2 months, 1 week ago by Andrew Ozz.
    • This reply was modified 2 months, 1 week ago by Andrew Ozz.

    I’m the maintainer of qTranslate on github and we are also encountering a case that looks related, it is a major issue. This seems to occur quite randomly, but so far I observed it only in combination with WP5.6, Firefox, and the Visual Editor – using the Classic Editor that many, many people still use. Sometimes the problem disappears just by reloading exactly the same page in a different tab…
    For reference:

    I observed one interesting event: for some reason (due to WP 5.6 + Firefox?), a listener i have on window.load even does not trigger all the time as it should, though i’m sure the addEventListener is called. If i add another dummy listener on window.load, this one is called all the time, which looks quite insane. Why would a window.load not be triggered?

    A few elements grabbed from the previous thread:

    > The issue seems to be that:
    > wp.oldEditor.initialize() is no longer firing and many plugins/blocks looking for this > event are no longer functioning.

    Could this be related to what I observed with window.load not firing properly in some event listener?

    > Uhh, I just reverted to an older jquery via a plugin – and that fixed it. :/

    That seems to confirm something is going wrong with some event.

    Same issue

    Any news?

    @azaozz could this issue be related to this fix you have been working on?

    Plugin Author Andrew Ozz


    @herrvigg yes, looks that way. Could you test qTranslate in WP 5.7-alpha to see if
    the fix at works?

    …for some reason (due to WP 5.6 + Firefox?), a listener i have on window.load event does not trigger all the time as it should

    Right, I’ve also seen few cases where $( window ).load() fires seemingly inconsistently in Firefox. Cannot successfully/consistently reproduce for now though.



    After upgrading to wp 5.6 the wp.editor.initialize() that I am using on a front-end form is not working anymore. I had to downgrade to have it back. Any solution/advice for that problem?

    There have been a whole bunch of people having similar problems aafter upgrading to WP 5.6.
    The root cause seems to be that the JQuery library version was updated by 5.6 and that has broken a lot of things.
    A temporary fix is to use the and wind back the library to a version that works for you.
    Hope this helps!

    I just installed 5.6 and got this exact same error. The JQuery Migrate plugin didn’t make a difference, sadly. I opted to restore the backup I made before the update, only to then have WP force me to re-install 5.6 before letting me go back to the site.

    Now I just have this message: “There has been a critical error on this website. Please check your site admin email inbox for instructions.”

    I haven’t received any email. I can’t even access the dashboard anymore.

Viewing 8 replies - 1 through 8 (of 8 total)
  • You must be logged in to reply to this topic.