Title: fatal error message returned when activating some plugins
Last modified: August 19, 2016

---

# fatal error message returned when activating some plugins

 *  [maynard10](https://wordpress.org/support/users/maynard10/)
 * (@maynard10)
 * [16 years, 7 months ago](https://wordpress.org/support/topic/fatal-error-message-returned-when-activating-some-plugins/)
 * Fatal error: Call to undefined function is_site_admin() in /home6/letscatc/public_html/
   wp-content/plugins/wordpress-related-posts/related-posts.php on line 81 That’s
   the message I get when trying to activate certain plugins. How to fix it?

Viewing 1 replies (of 1 total)

 *  [esmi](https://wordpress.org/support/users/esmi/)
 * (@esmi)
 * [16 years, 7 months ago](https://wordpress.org/support/topic/fatal-error-message-returned-when-activating-some-plugins/#post-1264626)
 * There isn’t a native WordPress function/conditional `is_site_admin()`.
 * [http://codex.wordpress.org/Conditional_Tags](http://codex.wordpress.org/Conditional_Tags)
 * Sounds like an old or faulty plugin.

Viewing 1 replies (of 1 total)

The topic ‘fatal error message returned when activating some plugins’ is closed 
to new replies.

## Tags

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

 * In: [Fixing WordPress](https://wordpress.org/support/forum/how-to-and-troubleshooting/)
 * 1 reply
 * 2 participants
 * Last reply from: [esmi](https://wordpress.org/support/users/esmi/)
 * Last activity: [16 years, 7 months ago](https://wordpress.org/support/topic/fatal-error-message-returned-when-activating-some-plugins/#post-1264626)
 * Status: not resolved

## Topics

### Topics with no replies

### Non-support topics

### Resolved topics

### Unresolved topics

### All topics