Support » Plugin: Fast Velocity Minify » jQuery is not defined at jquery-migrate.min.js

  • Resolved zuoothomas



    We’ve had the following error on some of our websites:

    jquery-migrate.min.js:2 Uncaught ReferenceError: jQuery is not defined
    at jquery-migrate.min.js:2

    Even when checking the option “skip deferring of jquery.js” we still have the error. The jquery-migrate.min.js is in the ignore list.

    Thanks in advance!

Viewing 8 replies - 1 through 8 (of 8 total)
  • Plugin Author Raul P.


    Do you have some other plugin interfering with the order of scripts? Or maybe moving the scripts to the footer?

    There is no plugin interfering with the order of the script if i recall correctly. Cache enabler doesn’t do that right?

    Is moving the scripts to the footer an option in FVM?

    Plugin Author Raul P.


    Sometimes people use plugins to either async or move scripts to the footer, that’s why I ask. Sometimes the theme itself has that functionality as well.

    The error you are seeing is because jQuery is either not loading at all, or because it is loading after jquery migrate, however, jquery-migrate has jquery as a dependency, so it must always load after jquery.

    If you are deferring or async jquery, then that could happen as well.

    What is the site url?
    Does it work if you disable JS processing on FVM?

    And when you enable it, does jQuery load after jquery migrate?



    Hey sorry for the long wait hehe.

    It is hard to test different settings because as soon as i save settings all cache gets cleared and that also gets rid the error. But it looks like if i disable JS processing on FVM it gets rid of the error, but as soon as i enable it the error comes back.

    You can check this site for an example of the error:

    removing /js/jquery/jquery-migrate.min.js from the default ignore list works as a workaround but i don’t think that is a smart way to fix the error?

    bumpdybump 😉

    Plugin Author Raul P.


    As I explained, you must have something changing the normal behaviour of scripts, OR you manually hardcode jquery migrate before the header, so it loads before the merged files.

    You say you have nothing changing the order of scripts, but you probably have:
    <!-- Speed of this site is optimised by WP Performance Score Booster plugin v1.9.2.2 - -->

    You can see where it shows jquery migrate being loaded before the fvm generated files.

    The fvm header file, only has jquery inside… so something is removing the jquery dependency on jquery… meaning, it loads earlier than jquery, and thus jquery is not yet defined.

    Please read the faqs:

    FVM should be the only thing allowed to optimize your js/css/html.

    Ah okay! I used WP PSB for the gzip compression, did not know it interfered with fvm. What way of gzip compression would you recommend in combination with FVM?

    Thanks for the help,



    If you are on Apache server and can edit your .htaccess file, follow my post here:

Viewing 8 replies - 1 through 8 (of 8 total)
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