Title: Fatal error on wp-activate.php
Last modified: August 21, 2016

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# Fatal error on wp-activate.php

 *  [pkirk](https://wordpress.org/support/users/pkirk/)
 * (@pkirk)
 * [12 years, 4 months ago](https://wordpress.org/support/topic/fatal-error-on-wp-activatephp/)
 * Dear developer,
    I would like to ask you to check the plugin’s behaviour with
   the wp-activate.php link that is sent to users to activate their account.
 * Because I’ve tried and I get a Fatal error
    `Fatal error: Call to undefined function
   is_mobile() in /var/www/example.com/public_html/wp-content/themes/theme/header.
   php on line XXX`
 * Really thanks for your time.
 * [https://wordpress.org/plugins/mobble/](https://wordpress.org/plugins/mobble/)

Viewing 2 replies - 1 through 2 (of 2 total)

 *  Plugin Author [Scott (@scottsweb)](https://wordpress.org/support/users/scottsweb/)
 * (@scottsweb)
 * [12 years, 4 months ago](https://wordpress.org/support/topic/fatal-error-on-wp-activatephp/#post-4773540)
 * Hi
    The only reason you would see this error is if the plugin is deactivated 
   AND your theme contains code that depends on mobble to be active.
 * Look within the file /var/www/example.com/public_html/wp-content/themes/theme/
   header.php for the call to `is_mobile()` and replace with something like:
 *     ```
       if (function_exists('is_mobile')) {
         if (is_mobile()) {
            // whatever code you had for mobiles
         } else {
            // whatever code you had for everything else
         }
       }
       ```
   
 *  Thread Starter [pkirk](https://wordpress.org/support/users/pkirk/)
 * (@pkirk)
 * [12 years, 4 months ago](https://wordpress.org/support/topic/fatal-error-on-wp-activatephp/#post-4773596)
 * Hi, and thanks for your reply.
 * The plugin was active, that was the problem.
    Seems like [http://www.example.com/wp-activate.php](http://www.example.com/wp-activate.php)
   doesn’t load the plugin or something like that.
 * Thanks for your time.

Viewing 2 replies - 1 through 2 (of 2 total)

The topic ‘Fatal error on wp-activate.php’ is closed to new replies.

 * ![](https://s.w.org/plugins/geopattern-icon/mobble_f5f5f5.svg)
 * [mobble](https://wordpress.org/plugins/mobble/)
 * [Frequently Asked Questions](https://wordpress.org/plugins/mobble/#faq)
 * [Support Threads](https://wordpress.org/support/plugin/mobble/)
 * [Active Topics](https://wordpress.org/support/plugin/mobble/active/)
 * [Unresolved Topics](https://wordpress.org/support/plugin/mobble/unresolved/)
 * [Reviews](https://wordpress.org/support/plugin/mobble/reviews/)

 * 2 replies
 * 2 participants
 * Last reply from: [pkirk](https://wordpress.org/support/users/pkirk/)
 * Last activity: [12 years, 4 months ago](https://wordpress.org/support/topic/fatal-error-on-wp-activatephp/#post-4773596)
 * Status: not resolved