Title: Undefined constant
Last modified: October 22, 2021

---

# Undefined constant

 *  Resolved [nusbizadclub](https://wordpress.org/support/users/nusbizadclub/)
 * (@nusbizadclub)
 * [4 years, 10 months ago](https://wordpress.org/support/topic/undefined-constant-10/)
 * Hi, I updated to the latest optimiser version 0.8.0 from 0.4.5, and I got the
   following error:
 *     ```
       Fatal error: Uncaught Error: Undefined constant "category_description" in /home/nusbizadclub/public_html/wp-content/themes/optimizer_pro_updated12_10_2021/framework/core-seo.php:26 Stack trace: #0 /home/nusbizadclub/public_html/wp-includes/template.php(772): require() #1 /home/nusbizadclub/public_html/wp-includes/template.php(716): load_template() #2 /home/nusbizadclub/public_html/wp-includes/general-template.php(204): locate_template() #3 /home/nusbizadclub/public_html/wp-content/themes/optimizer_pro_updated12_10_2021/header.php(27): get_template_part() #4 /home/nusbizadclub/public_html/wp-includes/template.php(770): require_once('/home/nusbizadc...') #5 /home/nusbizadclub/public_html/wp-includes/template.php(716): load_template() #6 /home/nusbizadclub/public_html/wp-includes/general-template.php(48): locate_template() #7 /home/nusbizadclub/public_html/wp-content/themes/optimizer_pro_updated12_10_2021/index.php(13): get_header() #8 /home/nusbizadclub/public_html/wp-includes/template-loader.php(106): include('/home/nusbizadc...') #9 /home/nusbizadclub/public_html/wp-blog-header.php(19): require_once('/home/nusbizadc...') #10 /home/nusbizadclub/public_html/index.php(17): require('/home/nusbizadc...') #11 {main} thrown in /home/nusbizadclub/public_html/wp-content/themes/optimizer_pro_updated12_10_2021/framework/core-seo.php on line 26
       There has been a critical error on this website.
       ```
   
 * Please advise on what to do.
    FYI: As of 20/10/2021 WordPress Version: 5.8.1 
   PHP version: 8.0 MySQL version: 5.6.51-cll-lve
 * The page I need help with: _[[log in](https://login.wordpress.org/?redirect_to=https%3A%2F%2Fwordpress.org%2Fsupport%2Ftopic%2Fundefined-constant-10%2F%3Foutput_format%3Dmd&locale=en_US)
   to see the link]_

Viewing 2 replies - 1 through 2 (of 2 total)

 *  [Harshad](https://wordpress.org/support/users/bornforphp/)
 * (@bornforphp)
 * [4 years, 10 months ago](https://wordpress.org/support/topic/undefined-constant-10/#post-14998267)
 * [@nusbizadclub](https://wordpress.org/support/users/nusbizadclub/) Our latest
   version for WP-Optimize is 3.1.2 are you talking about different optimiser plugin?
 *  Thread Starter [nusbizadclub](https://wordpress.org/support/users/nusbizadclub/)
 * (@nusbizadclub)
 * [4 years, 10 months ago](https://wordpress.org/support/topic/undefined-constant-10/#post-14998914)
 * Yeah I messed up haha
    I confused this with a WordPress Theme that had the exact
   same name. Thank you for replying though! Really appreciate it

Viewing 2 replies - 1 through 2 (of 2 total)

The topic ‘Undefined constant’ is closed to new replies.

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## Tags

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

 * 2 replies
 * 2 participants
 * Last reply from: [nusbizadclub](https://wordpress.org/support/users/nusbizadclub/)
 * Last activity: [4 years, 10 months ago](https://wordpress.org/support/topic/undefined-constant-10/#post-14998914)
 * Status: resolved