Title: Fatal Error: Undefined function
Last modified: August 22, 2016

---

# Fatal Error: Undefined function

 *  [GutsyBroad](https://wordpress.org/support/users/gutsybroad/)
 * (@gutsybroad)
 * [11 years, 4 months ago](https://wordpress.org/support/topic/fatal-error-undefined-function-5/)
 * Hi
    First… I am not a programmer. Second, when I tried to load the update to 
   4.1 (I think that’s what it was), I got the following error message: Fatal error:
   Call to undefined function wp_json_encode() in /home/content/31/11197731/html/
   wp-admin/includes/misc.php on line 668 my site is gutsybroad.com and to a surfer,
   it looks fine. But when I try to log in now I just get a blank page that gives
   me the above message. C.

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

 *  [Radices](https://wordpress.org/support/users/radices/)
 * (@radices)
 * [11 years, 4 months ago](https://wordpress.org/support/topic/fatal-error-undefined-function-5/#post-5598498)
 * Hi,
 * I can only suggest that you do a manual re-install of the 4.1 WordPress files.
   This is done using FTP or the File Manager in your Hosting Panel (Not the WordPress
   Dashboard).
 * DO NOT copy over the wp-content folder or wp-config.php file. This holds the 
   sites content and configuration.
 *  [Radices](https://wordpress.org/support/users/radices/)
 * (@radices)
 * [11 years, 4 months ago](https://wordpress.org/support/topic/fatal-error-undefined-function-5/#post-5598500)
 * I just saw this other thread that is similar to what your experiencing. It give
   good detail on the process.
 * [https://wordpress.org/support/topic/cant-login-to-site-after-41-update?replies=6](https://wordpress.org/support/topic/cant-login-to-site-after-41-update?replies=6)
 *  Thread Starter [GutsyBroad](https://wordpress.org/support/users/gutsybroad/)
 * (@gutsybroad)
 * [11 years, 4 months ago](https://wordpress.org/support/topic/fatal-error-undefined-function-5/#post-5598504)
 * Ah, yes, this all sounds helpful… I’ve never done anything like this…
 * what does this mean? “Get the latest WordPress zip (or tar.gz) file”
 * Is there a video I can follow? I don’t think I’m wordpress material…
 *  [Radices](https://wordpress.org/support/users/radices/)
 * (@radices)
 * [11 years, 4 months ago](https://wordpress.org/support/topic/fatal-error-undefined-function-5/#post-5598508)
 * You could maybe hire some help once and awhile.
 * [http://jobs.wordpress.net/](http://jobs.wordpress.net/)
 *  [WPyogi](https://wordpress.org/support/users/wpyogi/)
 * (@wpyogi)
 * [11 years, 4 months ago](https://wordpress.org/support/topic/fatal-error-undefined-function-5/#post-5598509)
 * **[@gutsybroad](https://wordpress.org/support/users/gutsybroad/)** – if you want
   to try this yourself, it’s not actually that hard – just a bit of new info and
   skills. Lots of people have been in your situation and learned by doing!
 * You’ll need to have FTP or Cpanel access to your files on the server –
    [http://codex.wordpress.org/FTP_Clients](http://codex.wordpress.org/FTP_Clients)
 * Your hosting company will be able to give you the FTP access info – that’s not
   part of WP.
 * >  what does this mean? “Get the latest WordPress zip (or tar.gz) file”
 * Just means download the latest version of WP from here:
 * [https://wordpress.org/download/](https://wordpress.org/download/) (blue button
   top right)

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

The topic ‘Fatal Error: Undefined function’ is closed to new replies.

## Tags

 * [fatal error](https://wordpress.org/support/topic-tag/fatal-error/)

 * In: [Fixing WordPress](https://wordpress.org/support/forum/how-to-and-troubleshooting/)
 * 5 replies
 * 3 participants
 * Last reply from: [WPyogi](https://wordpress.org/support/users/wpyogi/)
 * Last activity: [11 years, 4 months ago](https://wordpress.org/support/topic/fatal-error-undefined-function-5/#post-5598509)
 * Status: not resolved

## Topics

### Topics with no replies

### Non-support topics

### Resolved topics

### Unresolved topics

### All topics