Title: Error message when activating
Last modified: August 20, 2016

---

# Error message when activating

 *  [Bart van Poll](https://wordpress.org/support/users/bartvanpoll/)
 * (@bartvanpoll)
 * [14 years, 10 months ago](https://wordpress.org/support/topic/error-message-when-activating/)
 * I’m using Multi user installation and latest version of plugin.
 * On all blogs, the WordPress SEO plugin works great!
 * When I create a new blog though, I get many errors when the plugin is activated.
 * Warning: in_array() [function.in-array]: Wrong datatype for second argument in…/
   wp-content/plugins/wordpress-seo/inc/class-sitemaps.php on line 540

Viewing 5 replies - 1 through 5 (of 5 total)

 *  [gregfielding](https://wordpress.org/support/users/gregfielding/)
 * (@gregfielding)
 * [14 years, 9 months ago](https://wordpress.org/support/topic/error-message-when-activating/#post-2200207)
 * Getting this as well, along with errors adding widgets in new blogs. Do you get
   those errors as well?
 *  [richstrauss](https://wordpress.org/support/users/richstrauss/)
 * (@richstrauss)
 * [14 years, 9 months ago](https://wordpress.org/support/topic/error-message-when-activating/#post-2200212)
 * Hello, I am getting many errors too. I created a new site (subfolder) on a multisite
   installation yesterday and errors aare all over. On the dashboard of my new site
   I get things like:
 * Warning: in_array() [function.in-array]: Wrong datatype for second argument in/
   home/richardt/public_html/wp-content/plugins/wordpress-seo/inc/class-sitemaps.
   php on line 540
 * Fatal error: Cannot unset string offsets in /home/richardt/public_html/wp-content/
   plugins/wordpress-seo/wp-seo.php on line 90
 * Fatal error: Cannot unset string offsets in /home/richardt/public_html/wp-content/
   plugins/wordpress-seo/wp-seo.php on line 90
 * and then this one consistently at the top of my admin backend:
 * Warning: in_array() [function.in-array]: Wrong datatype for second argument in/
   home/richardt/public_html/wp-content/plugins/wordpress-seo/inc/class-sitemaps.
   php on line 540
 * I have tried deactivating WordPress SEO, deleting and re-installing.
 * I am running WordPress SEO Version 0.4.2 on WordPress version 3.2.1
 *  [richstrauss](https://wordpress.org/support/users/richstrauss/)
 * (@richstrauss)
 * [14 years, 9 months ago](https://wordpress.org/support/topic/error-message-when-activating/#post-2200213)
 * Also, when I try to update a post, it wont let me, I get the following:
 * Warning: in_array() [function.in-array]: Wrong datatype for second argument in/
   home/richardt/public_html/wp-content/plugins/wordpress-seo/inc/class-sitemaps.
   php on line 540
 * Warning: Cannot modify header information – headers already sent by (output started
   at /home/richardt/public_html/wp-content/plugins/wordpress-seo/inc/class-sitemaps.
   php:540) in /home/richardt/public_html/wp-includes/pluggable.php on line 934
 * Oh, and I have tried turning off network activation and turning it on per site
   too. Doesn’t work.
 * Thanks!
 *  [Dan (a11n)](https://wordpress.org/support/users/drawmyface/)
 * (@drawmyface)
 * [14 years, 9 months ago](https://wordpress.org/support/topic/error-message-when-activating/#post-2200267)
 * I’m getting a similar same error:
 * `Warning: in_array() expects parameter 2 to be array, string given in /public_html/
   wp-content/plugins/wordpress-seo/inc/class-sitemaps.php on line 538`
 * Anybody got anywhere with this yet?
 * It disappears if I disable XML sitemaps, but obviously I don’t want to do that.
 *  Thread Starter [Bart van Poll](https://wordpress.org/support/users/bartvanpoll/)
 * (@bartvanpoll)
 * [14 years, 9 months ago](https://wordpress.org/support/topic/error-message-when-activating/#post-2200268)
 * I still get the same error. Disabling XML Sitemaps is also not a solution for
   me. This is the error message I get:
 * Warning: in_array() [function.in-array]: Wrong datatype for second argument in/
   home/spotted/public_html/wp-content/plugins/wordpress-seo/inc/class-sitemaps.
   php on line 540
 * Warning: Cannot modify header information – headers already sent by (output started
   at /home/spotted/public_html/wp-content/plugins/wordpress-seo/inc/class-sitemaps.
   php:540) in /home/spotted/public_html/wp-includes/pluggable.php on line 934

Viewing 5 replies - 1 through 5 (of 5 total)

The topic ‘Error message when activating’ is closed to new replies.

 * ![](https://ps.w.org/wordpress-seo/assets/icon-256x256.gif?rev=3419908)
 * [Yoast SEO - Advanced SEO with real-time guidance and built-in AI](https://wordpress.org/plugins/wordpress-seo/)
 * [Frequently Asked Questions](https://wordpress.org/plugins/wordpress-seo/#faq)
 * [Support Threads](https://wordpress.org/support/plugin/wordpress-seo/)
 * [Active Topics](https://wordpress.org/support/plugin/wordpress-seo/active/)
 * [Unresolved Topics](https://wordpress.org/support/plugin/wordpress-seo/unresolved/)
 * [Reviews](https://wordpress.org/support/plugin/wordpress-seo/reviews/)

 * 5 replies
 * 4 participants
 * Last reply from: [Bart van Poll](https://wordpress.org/support/users/bartvanpoll/)
 * Last activity: [14 years, 9 months ago](https://wordpress.org/support/topic/error-message-when-activating/#post-2200268)
 * Status: not resolved