Title: Invalid Callback 'RWMB__Field'
Last modified: August 31, 2016

---

# Invalid Callback 'RWMB__Field'

 *  [max991](https://wordpress.org/support/users/max991/)
 * (@max991)
 * [10 years, 2 months ago](https://wordpress.org/support/topic/invalid-callback-rwmb_field/)
 * Hi,
 * I am getting the following error:
 * `( ! ) Warning: call_user_func() expects parameter 1 to be a valid callback, 
   class 'RWMB__Field' not found in \wp-content\plugins\meta-box\inc\meta-box.php
   on line 63`
 * As far as I can tell it only happens when i select “Option 2” in the code below.
   Any ideas?
 *     ```
       array(
                 'name'  => 'Options',
                 'id'    => self::$prefix . 'Options',
                 'type'  => 'select',
                 'options' => array(
                   'option-one' => 'Option 1',
                   'option-two' => 'Option 2',
                   'option-three' => 'Option 3',
                 ),
               ),
       ```
   
 * *Please note values are for showing purposes only.
 * Thanks in advanced.
 * [https://wordpress.org/plugins/meta-box/](https://wordpress.org/plugins/meta-box/)

Viewing 4 replies - 1 through 4 (of 4 total)

 *  Plugin Contributor [Manny Fleurmond](https://wordpress.org/support/users/funkatronic/)
 * (@funkatronic)
 * [10 years, 1 month ago](https://wordpress.org/support/topic/invalid-callback-rwmb_field/#post-7178067)
 * Can’t seem to replicate. Please get the latest version of the plugin and let 
   us know if it is still happening
 *  Thread Starter [max991](https://wordpress.org/support/users/max991/)
 * (@max991)
 * [10 years, 1 month ago](https://wordpress.org/support/topic/invalid-callback-rwmb_field/#post-7178069)
 * Hi,
 * Just updated plugin and yes still seems to be happening just odd it only happens
   for option 2 and option 1/3 are fine.
 * Thanks,
 *  Plugin Author [Anh Tran](https://wordpress.org/support/users/rilwis/)
 * (@rilwis)
 * [10 years ago](https://wordpress.org/support/topic/invalid-callback-rwmb_field/#post-7178081)
 * Hi [@max991](https://wordpress.org/support/users/max991/), can you please send
   me the full code for testing via the [Contact form](https://metabox.io/contact/)?
   Thanks!
 *  Thread Starter [max991](https://wordpress.org/support/users/max991/)
 * (@max991)
 * [10 years ago](https://wordpress.org/support/topic/invalid-callback-rwmb_field/#post-7178082)
 * Hi Tran,
 * Thanks for this I have submitted it via the form.
 * Kind regards,
    Max

Viewing 4 replies - 1 through 4 (of 4 total)

The topic ‘Invalid Callback 'RWMB__Field'’ is closed to new replies.

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 * 4 replies
 * 3 participants
 * Last reply from: [max991](https://wordpress.org/support/users/max991/)
 * Last activity: [10 years ago](https://wordpress.org/support/topic/invalid-callback-rwmb_field/#post-7178082)
 * Status: not resolved