Title: Error Upon Plugin Activation
Last modified: February 10, 2023

---

# Error Upon Plugin Activation

 *  [Flashpaper](https://wordpress.org/support/users/flashpaper/)
 * (@flashpaper)
 * [3 years, 3 months ago](https://wordpress.org/support/topic/error-upon-plugin-activation-2/)
 * Just downloaded and activated the plugin on a WordPress 6.11 website running 
   the Twenty-Twenty One theme. It’s a test site. Here’s the error that prints on
   the screen about 40 times:
 * Warning: array_key_exists() expects parameter 2 to be array, bool given in /raid/
   home/sixtesting/pennertesting6/provision63/wp-content/plugins/breadcrumb-navxt/
   includes/adminKit/class-mtekk_adminkit.php on line 531
 * Warning: Cannot use a scalar value as an array in /raid/home/sixtesting/pennertesting6/
   provision63/wp-content/plugins/breadcrumb-navxt/includes/adminKit/class-mtekk_adminkit.
   php on line 537
 * Any ideas? Looks like a really cool plugin. Hoping to try it out! 🙂
 * The page I need help with: _[[log in](https://login.wordpress.org/?redirect_to=https%3A%2F%2Fwordpress.org%2Fsupport%2Ftopic%2Ferror-upon-plugin-activation-2%2F%3Foutput_format%3Dmd&locale=en_US)
   to see the link]_

Viewing 1 replies (of 1 total)

 *  Plugin Author [John Havlik](https://wordpress.org/support/users/mtekk/)
 * (@mtekk)
 * [3 years, 3 months ago](https://wordpress.org/support/topic/error-upon-plugin-activation-2/#post-16460926)
 * From looking at the code, my assumption is `wp_kses_allowed_html()` is returning
   something other than an array on your site. This may be due to something hooking
   into one of the several filters within that function and not returning an array
   like it should. You could try deactivating all plugins other than Breadcrumb 
   NavXT to see if the warnings go away. What page/where do these PHP warnings end
   up showing up, is it on the front end of the site, on the Breadcrumb NavXT settings
   page, only on the plugins page immediately after activating, or somewhere else?

Viewing 1 replies (of 1 total)

The topic ‘Error Upon Plugin Activation’ is closed to new replies.

 * ![](https://ps.w.org/breadcrumb-navxt/assets/icon.svg?rev=1927103)
 * [Breadcrumb NavXT](https://wordpress.org/plugins/breadcrumb-navxt/)
 * [Support Threads](https://wordpress.org/support/plugin/breadcrumb-navxt/)
 * [Active Topics](https://wordpress.org/support/plugin/breadcrumb-navxt/active/)
 * [Unresolved Topics](https://wordpress.org/support/plugin/breadcrumb-navxt/unresolved/)
 * [Reviews](https://wordpress.org/support/plugin/breadcrumb-navxt/reviews/)

 * 1 reply
 * 2 participants
 * Last reply from: [John Havlik](https://wordpress.org/support/users/mtekk/)
 * Last activity: [3 years, 3 months ago](https://wordpress.org/support/topic/error-upon-plugin-activation-2/#post-16460926)
 * Status: not resolved