Title: Error array_key_exists() in backend
Last modified: November 9, 2017

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# Error array_key_exists() in backend

 *  Resolved [frances2823](https://wordpress.org/support/users/frances2823/)
 * (@frances2823)
 * [8 years, 6 months ago](https://wordpress.org/support/topic/error-array_key_exists-in-backend/)
 * Hello,
 * on a multisite configuration, in the backend I have errors showing in posts parts.
   
   When I write a new or edit an existing post, I have two blocks “categories” in
   the right col, instead of one. Both block are the same. The first is ok, the 
   second block is showing errors in it :
 *     ```
       Warning: array_key_exists() expects parameter 2 to be array, boolean given in mywebsite\wp-content\plugins\collapsing-category-list\classes\class-walker-category-checklist.php on line 127
       Warning: array_key_exists() expects parameter 2 to be array, boolean given in mywebsite\wp-content\plugins\collapsing-category-list\classes\class-walker-category-checklist.php on line 41
       ```
   
 * I have both errors for each categories
 * Thanks

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

 *  Plugin Author [migrad](https://wordpress.org/support/users/migrad/)
 * (@migrad)
 * [8 years, 6 months ago](https://wordpress.org/support/topic/error-array_key_exists-in-backend/#post-9667490)
 * Version 0.5.4 fixed the warnings. Could you say me what WordPress version is?
 *  Plugin Author [migrad](https://wordpress.org/support/users/migrad/)
 * (@migrad)
 * [8 years, 6 months ago](https://wordpress.org/support/topic/error-array_key_exists-in-backend/#post-9667575)
 * Well, I tested in 4.8.3 and I don’t see two category widget in admin page when
   edit a post. Is possible what you have other plugin for the categories widget
   in admin pages?

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

The topic ‘Error array_key_exists() in backend’ is closed to new replies.

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 * 2 replies
 * 2 participants
 * Last reply from: [migrad](https://wordpress.org/support/users/migrad/)
 * Last activity: [8 years, 6 months ago](https://wordpress.org/support/topic/error-array_key_exists-in-backend/#post-9667575)
 * Status: resolved