Title: FATAL ERROR help
Last modified: August 31, 2016

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# FATAL ERROR help

 *  [amandadesouza](https://wordpress.org/support/users/amandadesouza/)
 * (@amandadesouza)
 * [10 years, 5 months ago](https://wordpress.org/support/topic/fatal-error-help-46/)
 * I’m not a big technical person, I’ve been running my wordpress site though for
   5 years without a lot of trouble. Today I downloaded the Optimizer theme and 
   got this fatal error:
 * Fatal error: Call to undefined function is_customize_preview() in /home/amandade/
   public_html/wp-content/themes/optimizer/lib/functions/core.php on line 67
 * I have no idea what to do. Please help!
 * Thanks!

Viewing 1 replies (of 1 total)

 *  Theme Author [OptimizerWP](https://wordpress.org/support/users/layerthemes/)
 * (@layerthemes)
 * [10 years, 5 months ago](https://wordpress.org/support/topic/fatal-error-help-46/#post-6903184)
 * [@amandadesouza](https://wordpress.org/support/users/amandadesouza/) Sounds like
   you are using a very old version of wordpress. please update to wordpress 4.4
   and the issue should be resolved.
 * Regards

Viewing 1 replies (of 1 total)

The topic ‘FATAL ERROR help’ is closed to new replies.

 * ![](https://i0.wp.com/themes.svn.wordpress.org/optimizer/0.7.4/screenshot.png)
 * Optimizer
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 * [Active Topics](https://wordpress.org/support/theme/optimizer/active/)
 * [Unresolved Topics](https://wordpress.org/support/theme/optimizer/unresolved/)
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 * 1 reply
 * 2 participants
 * Last reply from: [OptimizerWP](https://wordpress.org/support/users/layerthemes/)
 * Last activity: [10 years, 5 months ago](https://wordpress.org/support/topic/fatal-error-help-46/#post-6903184)
 * Status: not resolved