Title: Warning: Last modified: August 20, 2016 --- # Warning: * Resolved [yoramzara](https://wordpress.org/support/users/yoramzara/) * (@yoramzara) * [13 years, 2 months ago](https://wordpress.org/support/topic/warning-21/) * This is the message I got when I upgraded the plugin now * Warning: array_diff() [function.array-diff]: Argument #1 is not an array in / home/avelim2/public_html/wp-content/plugins/restrict-categories/restrict-categories. php on line 442 * Warning: array_values() expects parameter 1 to be array, null given in * What is this? * [http://wordpress.org/extend/plugins/restrict-categories/](http://wordpress.org/extend/plugins/restrict-categories/) Viewing 15 replies - 1 through 15 (of 16 total) 1 [2](https://wordpress.org/support/topic/warning-21/page/2/?output_format=md) [→](https://wordpress.org/support/topic/warning-21/page/2/?output_format=md) * [RyanThaDude](https://wordpress.org/support/users/ryanthadude/) * (@ryanthadude) * [13 years, 2 months ago](https://wordpress.org/support/topic/warning-21/#post-3550720) * I’m getting it too, and it’s causing problems while posting articles due to “ Headers already sent”. * [saintandrews](https://wordpress.org/support/users/saintandrews/) * (@saintandrews) * [13 years, 2 months ago](https://wordpress.org/support/topic/warning-21/#post-3550838) * Same here. Reverted until fixed. * [Contemplative Computing](https://wordpress.org/support/users/contemplative-computing/) * (@contemplative-computing) * [13 years, 2 months ago](https://wordpress.org/support/topic/warning-21/#post-3550843) * Same here. * [Contemplative Computing](https://wordpress.org/support/users/contemplative-computing/) * (@contemplative-computing) * [13 years, 2 months ago](https://wordpress.org/support/topic/warning-21/#post-3550846) * I commented out the problem clause and everything seems to be working okay for now. Will look out for an update. * Plugin Author [Matthew Muro](https://wordpress.org/support/users/mmuro/) * (@mmuro) * [13 years, 2 months ago](https://wordpress.org/support/topic/warning-21/#post-3550855) * What PHP version are you using and in what scenarios can this be reproduced? * I tried this on PHP 5.2.17 and 5.3.5 and could not get this error. I went through and saved categories for Roles and Users, checked the Posts screen, added a Post, reset the settings. Am I missing something? * Thread Starter [yoramzara](https://wordpress.org/support/users/yoramzara/) * (@yoramzara) * [13 years, 2 months ago](https://wordpress.org/support/topic/warning-21/#post-3550864) * 5.3.8 * [RyanThaDude](https://wordpress.org/support/users/ryanthadude/) * (@ryanthadude) * [13 years, 2 months ago](https://wordpress.org/support/topic/warning-21/#post-3550865) * My host is using 5.3.15 and my local Ubuntu test server is using 5.4.6. The error would only appear in /wp-admin. I also reverted back on my production server and the error went away. * EDIT: I just tested it on my test server and the warning appears at the top of every page in /wp-admin. Making any changes causes “Headers already sent” and the page fails to load. * Plugin Author [Matthew Muro](https://wordpress.org/support/users/mmuro/) * (@mmuro) * [13 years, 2 months ago](https://wordpress.org/support/topic/warning-21/#post-3550887) * You can try replacing line 441 with the following and see if the error goes away: ` if ( is_array( $settings_user ) && array_key_exists( $user_login . '_user_cats', $settings_user ) )` * Thread Starter [yoramzara](https://wordpress.org/support/users/yoramzara/) * (@yoramzara) * [13 years, 2 months ago](https://wordpress.org/support/topic/warning-21/#post-3550888) * I am sot a coder. It is easier for me to stay with 2.5 that has no issues. * Plugin Author [Matthew Muro](https://wordpress.org/support/users/mmuro/) * (@mmuro) * [13 years, 2 months ago](https://wordpress.org/support/topic/warning-21/#post-3550893) * I understand. It’s just a single line, though and you’d be helping out others with similar problems. * If someone else wants to test this, I’d appreciate it. * [Dani](https://wordpress.org/support/users/danicasati/) * (@danicasati) * [13 years, 2 months ago](https://wordpress.org/support/topic/warning-21/#post-3550903) * Same problem. I get this warning everywhere on my control panel. * Plugin Author [Matthew Muro](https://wordpress.org/support/users/mmuro/) * (@mmuro) * [13 years, 2 months ago](https://wordpress.org/support/topic/warning-21/#post-3550904) * [@danicasati](https://wordpress.org/support/users/danicasati/), what PHP version are you running? If you can try replacing line 441 with the above code to see if that works, that’d help. * [Dani](https://wordpress.org/support/users/danicasati/) * (@danicasati) * [13 years, 2 months ago](https://wordpress.org/support/topic/warning-21/#post-3550906) * Yes, it works. Could you patch this issue in next version? * Plugin Author [Matthew Muro](https://wordpress.org/support/users/mmuro/) * (@mmuro) * [13 years, 2 months ago](https://wordpress.org/support/topic/warning-21/#post-3550909) * Cool, will do. Thanks for testing! * Plugin Author [Matthew Muro](https://wordpress.org/support/users/mmuro/) * (@mmuro) * [13 years, 2 months ago](https://wordpress.org/support/topic/warning-21/#post-3550918) * The fix has been integrated in 2.6.1, so give that a try and let me know if it doesn’t work. Viewing 15 replies - 1 through 15 (of 16 total) 1 [2](https://wordpress.org/support/topic/warning-21/page/2/?output_format=md) [→](https://wordpress.org/support/topic/warning-21/page/2/?output_format=md) The topic ‘Warning:’ is closed to new replies. * ![](https://s.w.org/plugins/geopattern-icon/restrict-categories.svg) * [Restrict Categories](https://wordpress.org/plugins/restrict-categories/) * [Frequently Asked Questions](https://wordpress.org/plugins/restrict-categories/#faq) * [Support Threads](https://wordpress.org/support/plugin/restrict-categories/) * [Active Topics](https://wordpress.org/support/plugin/restrict-categories/active/) * [Unresolved Topics](https://wordpress.org/support/plugin/restrict-categories/unresolved/) * [Reviews](https://wordpress.org/support/plugin/restrict-categories/reviews/) * 16 replies * 6 participants * Last reply from: [RyanThaDude](https://wordpress.org/support/users/ryanthadude/) * Last activity: [13 years, 2 months ago](https://wordpress.org/support/topic/warning-21/page/2/#post-3550962) * Status: resolved