Title: Can’t activate plugin – Warning: call_user_func_array
Last modified: June 13, 2017

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# Can’t activate plugin – Warning: call_user_func_array

 *  Resolved [MosesAB](https://wordpress.org/support/users/mosesab/)
 * (@mosesab)
 * [8 years, 11 months ago](https://wordpress.org/support/topic/cant-activate-plugin-warning-call_user_func_array-3/)
 * Hi
 * When I try to activatie the plugin it says:
 * Warning: call_user_func_array() expects parameter 1 to be a valid callback, class‘
   RWMB_Simple_Proportions_Field’ does not have a method ‘normalize’ in /home/httpd/
   vhosts/weidmann-ag.ch/httpdocs/assets/plugins/wp-contact-slider/inc/meta-box/
   inc/field.php on line 510
 * Warning: call_user_func_array() expects parameter 1 to be a valid callback, class‘
   RWMB_Simple_Proportions_Field’ does not have a method ‘normalize’ in /home/httpd/
   vhosts/weidmann-ag.ch/httpdocs/assets/plugins/wp-contact-slider/inc/meta-box/
   inc/field.php on line 510
 * Warning: call_user_func_array() expects parameter 1 to be a valid callback, class‘
   RWMB_Fancy_Category_Field’ does not have a method ‘normalize’ in /home/httpd/
   vhosts/weidmann-ag.ch/httpdocs/assets/plugins/wp-contact-slider/inc/meta-box/
   inc/field.php on line 510
 * Warning: call_user_func_array() expects parameter 1 to be a valid callback, class‘
   RWMB_Simple_Proportions_Field’ does not have a method ‘normalize’ in /home/httpd/
   vhosts/weidmann-ag.ch/httpdocs/assets/plugins/wp-contact-slider/inc/meta-box/
   inc/field.php on line 510
 * Warning: call_user_func_array() expects parameter 1 to be a valid callback, class‘
   RWMB_Dropdown_Pages_Field’ does not have a method ‘normalize’ in /home/httpd/
   vhosts/weidmann-ag.ch/httpdocs/assets/plugins/wp-contact-slider/inc/meta-box/
   inc/field.php on line 510
 * Warning: call_user_func_array() expects parameter 1 to be a valid callback, class‘
   RWMB_Fancy_Category_Field’ does not have a method ‘normalize’ in /home/httpd/
   vhosts/weidmann-ag.ch/httpdocs/assets/plugins/wp-contact-slider/inc/meta-box/
   inc/field.php on line 510
 * Warning: call_user_func_array() expects parameter 1 to be a valid callback, class‘
   RWMB_Simple_Proportions_Field’ does not have a method ‘normalize’ in /home/httpd/
   vhosts/weidmann-ag.ch/httpdocs/assets/plugins/wp-contact-slider/inc/meta-box/
   inc/field.php on line 510
 * Warning: call_user_func_array() expects parameter 1 to be a valid callback, class‘
   RWMB_Simple_Proportions_Field’ does not have a method ‘normalize’ in /home/httpd/
   vhosts/weidmann-ag.ch/httpdocs/assets/plugins/wp-contact-slider/inc/meta-box/
   inc/field.php on line 510
 * Warning: call_user_func_array() expects parameter 1 to be a valid callback, class‘
   RWMB_Dropdown_Pages_Field’ does not have a method ‘normalize’ in /home/httpd/
   vhosts/weidmann-ag.ch/httpdocs/assets/plugins/wp-contact-slider/inc/meta-box/
   inc/field.php on line 510
 * Warning: call_user_func_array() expects parameter 1 to be a valid callback, class‘
   RWMB_Simple_Proportions_Field’ does not have a method ‘normalize’ in /home/httpd/
   vhosts/weidmann-ag.ch/httpdocs/assets/plugins/wp-contact-slider/inc/meta-box/
   inc/field.php on line 510
 * Warning: call_user_func_array() expects parameter 1 to be a valid callback, class‘
   RWMB_Fancy_Category_Field’ does not have a method ‘normalize’ in /home/httpd/
   vhosts/weidmann-ag.ch/httpdocs/assets/plugins/wp-contact-slider/inc/meta-box/
   inc/field.php on line 510
 * Warning: call_user_func_array() expects parameter 1 to be a valid callback, class‘
   RWMB_Simple_Proportions_Field’ does not have a method ‘normalize’ in /home/httpd/
   vhosts/weidmann-ag.ch/httpdocs/assets/plugins/wp-contact-slider/inc/meta-box/
   inc/field.php on line 510
 * Warning: call_user_func_array() expects parameter 1 to be a valid callback, class‘
   RWMB_Fancy_Category_Field’ does not have a method ‘normalize’ in /home/httpd/
   vhosts/weidmann-ag.ch/httpdocs/assets/plugins/wp-contact-slider/inc/meta-box/
   inc/field.php on line 510
 * Warning: call_user_func_array() expects parameter 1 to be a valid callback, class‘
   RWMB_Simple_Proportions_Field’ does not have a method ‘normalize’ in /home/httpd/
   vhosts/weidmann-ag.ch/httpdocs/assets/plugins/wp-contact-slider/inc/meta-box/
   inc/field.php on line 510
 * Warning: call_user_func_array() expects parameter 1 to be a valid callback, class‘
   RWMB_Dropdown_Pages_Field’ does not have a method ‘normalize’ in /home/httpd/
   vhosts/weidmann-ag.ch/httpdocs/assets/plugins/wp-contact-slider/inc/meta-box/
   inc/field.php on line 510
 * Warning: call_user_func_array() expects parameter 1 to be a valid callback, class‘
   RWMB_Simple_Proportions_Field’ does not have a method ‘normalize’ in /home/httpd/
   vhosts/weidmann-ag.ch/httpdocs/assets/plugins/wp-contact-slider/inc/meta-box/
   inc/field.php on line 510
 * Warning: call_user_func_array() expects parameter 1 to be a valid callback, class‘
   RWMB_Simple_Proportions_Field’ does not have a method ‘normalize’ in /home/httpd/
   vhosts/weidmann-ag.ch/httpdocs/assets/plugins/wp-contact-slider/inc/meta-box/
   inc/field.php on line 510
 * Warning: call_user_func_array() expects parameter 1 to be a valid callback, class‘
   RWMB_Simple_Proportions_Field’ does not have a method ‘normalize’ in /home/httpd/
   vhosts/weidmann-ag.ch/httpdocs/assets/plugins/wp-contact-slider/inc/meta-box/
   inc/field.php on line 510
 * Warning: call_user_func_array() expects parameter 1 to be a valid callback, class‘
   RWMB_Fancy_Category_Field’ does not have a method ‘normalize’ in /home/httpd/
   vhosts/weidmann-ag.ch/httpdocs/assets/plugins/wp-contact-slider/inc/meta-box/
   inc/field.php on line 510
 * Warning: call_user_func_array() expects parameter 1 to be a valid callback, class‘
   RWMB_Simple_Proportions_Field’ does not have a method ‘normalize’ in /home/httpd/
   vhosts/weidmann-ag.ch/httpdocs/assets/plugins/wp-contact-slider/inc/meta-box/
   inc/field.php on line 510
 * Warning: call_user_func_array() expects parameter 1 to be a valid callback, class‘
   RWMB_Fancy_Category_Field’ does not have a method ‘normalize’ in /home/httpd/
   vhosts/weidmann-ag.ch/httpdocs/assets/plugins/wp-contact-slider/inc/meta-box/
   inc/field.php on line 510
 * Any suggestions?
    Thank you Moses

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

 *  Plugin Author [WPExperts.io](https://wordpress.org/support/users/wpexpertsio/)
 * (@wpexpertsio)
 * [8 years, 11 months ago](https://wordpress.org/support/topic/cant-activate-plugin-warning-call_user_func_array-3/#post-9230944)
 * Hi there!
 * Seems like here WP Contact Slider is conflicting with some other plugin. Can 
   you share your theme and list of plugins at support[at]wpepxerts[dot]io so that
   we can try to dig and fix it for you.
 * Thanks!
 *  Plugin Author [WPExperts.io](https://wordpress.org/support/users/wpexpertsio/)
 * (@wpexpertsio)
 * [8 years, 11 months ago](https://wordpress.org/support/topic/cant-activate-plugin-warning-call_user_func_array-3/#post-9294478)
 * Hi there!
 * We were experimenting WordPress Contact slider with theme the7 and saw the above
   mentioned conflicts. And while digging for the fix here is what we found from
   the author of the Meta Box API which we both are using.
 * [Here you can view the comment of the Meta Box author](https://wordpress.org/support/topic/conflict-with-visual-composer-and-other-fields/#post-8374263)
 * According to him;
 * > The errors above come from the custom code of your theme dt-the7. They’re not
   > in the code of the Meta Box. Please contact the theme author to make that code
   > compatible with Meta Box.
 * So you need to contact your theme author to update their meta box API to avoid
   these sort of conflicts with other plugins using the same Meta Box API.
 * Let us know if still you have any thing we can help you with.
 * Thanks!

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

The topic ‘Can’t activate plugin – Warning: call_user_func_array’ is closed to new
replies.

 * ![](https://ps.w.org/wp-contact-slider/assets/icon-256x256.png?rev=3171432)
 * [WP Contact Slider – Contact Form Slider Widget](https://wordpress.org/plugins/wp-contact-slider/)
 * [Frequently Asked Questions](https://wordpress.org/plugins/wp-contact-slider/#faq)
 * [Support Threads](https://wordpress.org/support/plugin/wp-contact-slider/)
 * [Active Topics](https://wordpress.org/support/plugin/wp-contact-slider/active/)
 * [Unresolved Topics](https://wordpress.org/support/plugin/wp-contact-slider/unresolved/)
 * [Reviews](https://wordpress.org/support/plugin/wp-contact-slider/reviews/)

## Tags

 * [activation error](https://wordpress.org/support/topic-tag/activation-error/)

 * 2 replies
 * 2 participants
 * Last reply from: [WPExperts.io](https://wordpress.org/support/users/wpexpertsio/)
 * Last activity: [8 years, 11 months ago](https://wordpress.org/support/topic/cant-activate-plugin-warning-call_user_func_array-3/#post-9294478)
 * Status: resolved