JavaScript Error Preview Page with ACF Pro

• mikegriffinn

• December 24, 2015 at 5:16 am

On WP 4.2.2 (original version) and WP 4.4 latest, using ACF 5.3.2.2 when I try to preview or publish a page, I get “Uncaught TypeError: Cannot read property ‘length’ of undefined.” and then a long list of jquery modules after load-scripts.php If I deactivate ACF the error goes away.

I put in a support ticket but haven’t received a confirmation so I thought I’d ask here.

Here’s the error on my dev box with WP 4.2.5. It is the same on the client’s production server with WP 4.4

Uncaught TypeError: Cannot read property 'length' of undefined
http://mobee.dev/wp-admin/load-scripts.php?c=0&load%5B%5D=jquery-core,jquery-migrate,utils,jquery-ui-widget,jquery-ui-position,jquery-ui-core,jquery-ui-mouse,jquery-ui-sortable,thickbox,&load%5B%5D=plupload,jquery-ui-resizable,jquery-ui-datepicker,jquery-ui-draggable,jquery-ui-slider,jquery-touch-punch,iris,wp-color-picker,j&load%5B%5D=query-ui-progressbar,jquery-ui-button,jquery-ui-dialog&ver=4.2.5 line 2

• John Huebner

• December 28, 2015 at 7:43 am

On one of my test sites with only ACF installed I am not seeing this JS error when I save or preview a post.

Try deactivating other plugins to narrow down the where the conflict might be.

Do you have a plugin installed that’s deferring script loading? There have been issues with this in the past and reported here on the forum.

• EduFer445

• January 14, 2016 at 8:01 pm

Hi,

Following that thread, I’m experiencing pretty much the same error by trying to preview a page. I just upgrade WP on 4.4.1 and ACF on 4.4.5 but previous configuration was working fine.

When I try to preview a page, I get a server error 500. I’ve deactived one by one all the other pluggins of my site, and the problems only disappear when I deactivate the ACF.

Thx for your support on that.