Title: Fatal error when activating plugin
Last modified: August 30, 2016

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# Fatal error when activating plugin

 *  [adiuvo](https://wordpress.org/support/users/adiuvo/)
 * (@adiuvo)
 * [10 years, 10 months ago](https://wordpress.org/support/topic/fatal-error-when-activating-plugin-24/)
 * Hi,
 * On of our customers wants to use your plugin. I’ve tried installing it, but i
   encounter the following error:
 * `Fatal error: Class 'CMB_Field' not found in /somepath/public_html/wp-content/
   plugins/wpbroadbean/functions/admin/metaboxes.php on line 61`
 * After investigating the issue i found out our plugin (Maleo) is also using CMB.
   But doesn’t load all the files your plugin needs, i can’t drop this theme so 
   is there an alternative solution?
 * Thanks.
 * Robbert
 * [https://wordpress.org/plugins/wpbroadbean/](https://wordpress.org/plugins/wpbroadbean/)

Viewing 3 replies - 1 through 3 (of 3 total)

 *  Plugin Author [Mark Wilkinson](https://wordpress.org/support/users/wpmarkuk/)
 * (@wpmarkuk)
 * [10 years, 10 months ago](https://wordpress.org/support/topic/fatal-error-when-activating-plugin-24/#post-6355956)
 * This plugin checks whether there is a class that already exists named `CMB_Meta_Box`.
   If there is the CMB meta boxes code is not loaded as it should already be available
   probably being added by another plugin or theme.
 * Therefore it must be that your plugin or theme has a loaded a class with the 
   name `CMB_Meta_Box` which is different from the meta box framework being used
   here, which is this one:
 * [https://github.com/humanmade/Custom-Meta-Boxes](https://github.com/humanmade/Custom-Meta-Boxes)
 *  Thread Starter [adiuvo](https://wordpress.org/support/users/adiuvo/)
 * (@adiuvo)
 * [10 years, 10 months ago](https://wordpress.org/support/topic/fatal-error-when-activating-plugin-24/#post-6355958)
 * Thanks for you answer.
 * I can take a look if the theme is updateble with your version.
 * thanks
 *  Plugin Author [Mark Wilkinson](https://wordpress.org/support/users/wpmarkuk/)
 * (@wpmarkuk)
 * [10 years, 10 months ago](https://wordpress.org/support/topic/fatal-error-when-activating-plugin-24/#post-6355959)
 * If the theme is loading the same meta box framework as I linked to above, but
   not loading the entire framework then I think that is a problem with that theme.
   It would be better if the theme you mention loads the entire framework, or rename
   the class.
 * Essentially what I am saying here is that I think this plugin does it the right
   way.

Viewing 3 replies - 1 through 3 (of 3 total)

The topic ‘Fatal error when activating plugin’ is closed to new replies.

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 * 3 replies
 * 2 participants
 * Last reply from: [Mark Wilkinson](https://wordpress.org/support/users/wpmarkuk/)
 * Last activity: [10 years, 10 months ago](https://wordpress.org/support/topic/fatal-error-when-activating-plugin-24/#post-6355959)
 * Status: not resolved