Title: Fatal error installing 3.9.1
Last modified: August 21, 2016

---

# Fatal error installing 3.9.1

 *  [taffy24](https://wordpress.org/support/users/taffy24/)
 * (@taffy24)
 * [11 years, 11 months ago](https://wordpress.org/support/topic/fatal-error-installing-391/)
 * First, let me admit that I only blog about once a year, and I know next-to-nothing
   about coding, etc.
 * I was trying to update my blog this past week, in preparation for a few new posts,
   when “Fatal error: Call to undefined function wp_safe_remote_get() in /home/content/
   73/5477273/html/tafulton/wp-admin/includes/file.php on line 497” came up.
 * Being somewhat stubborn and afraid of learning more advanced technology, I tried
   ignoring this error and publishing a post instead of addressing the problem. 
   This was met with “Fatal error: Call to undefined function wp_unslash() in /home/
   content/73/5477273/html/tafulton/wp-admin/includes/post.php on line 740”
 * When writing the test post, I also noticed my categories box was messed up, reading“
   Warning: call_user_func() [function.call-user-func]: First argument is expected
   to be a valid callback in /home/content/73/5477273/html/tafulton/wp-admin/includes/
   template.php on line 985”.
 * I’ve never played around with the code of my site, so I’m really not sure what’s
   causing this error. I’m hesitant about going in and fixing the code myself, because(
   1) I don’t quite understand how to back things up, and (2) I’m afraid I would
   somehow crash my site.
 * This may be a very stupid question, but is there an easy way to resolve this?

Viewing 1 replies (of 1 total)

 *  Moderator [James Huff](https://wordpress.org/support/users/macmanx/)
 * (@macmanx)
 * [11 years, 11 months ago](https://wordpress.org/support/topic/fatal-error-installing-391/#post-5075795)
 * It could simply be an incompatible plugin or theme.
 * Try deactivating all plugins. If that resolves the issue, reactivate each one
   individually until you find the cause.
 * If that does not resolve the issue, try switching to the Twenty Fourteen theme
   to rule-out a theme-specific issue (theme functions can interfere like plugins).

Viewing 1 replies (of 1 total)

The topic ‘Fatal error installing 3.9.1’ is closed to new replies.

## Tags

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

 * In: [Fixing WordPress](https://wordpress.org/support/forum/how-to-and-troubleshooting/)
 * 1 reply
 * 2 participants
 * Last reply from: [James Huff](https://wordpress.org/support/users/macmanx/)
 * Last activity: [11 years, 11 months ago](https://wordpress.org/support/topic/fatal-error-installing-391/#post-5075795)
 * Status: not resolved

## Topics

### Topics with no replies

### Non-support topics

### Resolved topics

### Unresolved topics

### All topics