Title: Preview Post Error: Class does not have a method
Last modified: August 31, 2016

---

# Preview Post Error: Class does not have a method

 *  [areessmith123](https://wordpress.org/support/users/areessmith123/)
 * (@areessmith123)
 * [9 years, 11 months ago](https://wordpress.org/support/topic/preview-post-error-class-does-not-have-a-method/)
 * Upon clicking the button “Preview Post” on our website, it takes us to a blank
   webpage and displays this error:
 * Warning: call_user_func_array() expects parameter 1 to be a valid callback, class‘
   RecentPostsWidget’ does not have a method ‘flush_widget_cache’ in /var/sites/
   s/steponefinance.co.uk/public_html/wp-includes/plugin.php on line 525
 * Warning: Cannot modify header information – headers already sent by (output started
   at /var/sites/s/steponefinance.co.uk/public_html/wp-includes/plugin.php:525) 
   in /var/sites/s/steponefinance.co.uk/public_html/wp-includes/pluggable.php on
   line 1171
 * We are fully up to date, including plugins. any help would be greatly appreciated.

Viewing 1 replies (of 1 total)

 *  Moderator [t-p](https://wordpress.org/support/users/t-p/)
 * (@t-p)
 * [9 years, 11 months ago](https://wordpress.org/support/topic/preview-post-error-class-does-not-have-a-method/#post-7410863)
 * Try reviewing this codex to solve header already sent problem: [http://codex.wordpress.org/FAQ_Troubleshooting#How_do_I_solve_the_Headers_already_sent_warning_problem.3F](http://codex.wordpress.org/FAQ_Troubleshooting#How_do_I_solve_the_Headers_already_sent_warning_problem.3F)

Viewing 1 replies (of 1 total)

The topic ‘Preview Post Error: Class does not have a method’ is closed to new replies.

## Tags

 * [class](https://wordpress.org/support/topic-tag/class/)
 * [method](https://wordpress.org/support/topic-tag/method/)
 * [post](https://wordpress.org/support/topic-tag/post/)

 * In: [Fixing WordPress](https://wordpress.org/support/forum/how-to-and-troubleshooting/)
 * 1 reply
 * 2 participants
 * Last reply from: [t-p](https://wordpress.org/support/users/t-p/)
 * Last activity: [9 years, 11 months ago](https://wordpress.org/support/topic/preview-post-error-class-does-not-have-a-method/#post-7410863)
 * Status: not resolved

## Topics

### Topics with no replies

### Non-support topics

### Resolved topics

### Unresolved topics

### All topics