Title: Error 500 > undefined function
Last modified: February 8, 2018

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# Error 500 > undefined function

 *  Resolved [lundien8](https://wordpress.org/support/users/lundien8/)
 * (@lundien8)
 * [8 years, 4 months ago](https://wordpress.org/support/topic/error-500-undefined-function/)
 * Hi everyone,
    i tried today a new install of the plugin and i get an error 500
   when i try to open the ACFFA field. Instead of listing the icons it says “loading
   error”. I see the error 500 in the ajax call, and when i look at the php log 
   i can find this error message :
 * “PHP Fatal error: Call to undefined function acf_send_ajax_results() in [path_to_my_vhost]/
   wp-content/plugins/advanced-custom-fields-font-awesome/assets/inc/class-ACFFAL.
   php”
 * Do you have any idea of what happened ?
 * Thanks for your help.

Viewing 1 replies (of 1 total)

 *  Plugin Author [Matt Keys](https://wordpress.org/support/users/mattkeys/)
 * (@mattkeys)
 * [8 years, 4 months ago](https://wordpress.org/support/topic/error-500-undefined-function/#post-9952429)
 * It sounds like you probably have an outdated version of Advanced Custom Fields
   Pro installed. The acf_send_ajax_results() function that it cannot find was added
   to ACF Pro in version 5.4.0 (5.6.8 is latest version at the time I write this).
   Can you confirm if this is your problem?

Viewing 1 replies (of 1 total)

The topic ‘Error 500 > undefined function’ is closed to new replies.

 * ![](https://ps.w.org/advanced-custom-fields-font-awesome/assets/icon-256x256.
   jpg?rev=3435775)
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 * 1 reply
 * 2 participants
 * Last reply from: [Matt Keys](https://wordpress.org/support/users/mattkeys/)
 * Last activity: [8 years, 4 months ago](https://wordpress.org/support/topic/error-500-undefined-function/#post-9952429)
 * Status: resolved