Title: PHP Warning: Undefined array key “excerptLength”
Last modified: June 24, 2026

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# PHP Warning: Undefined array key “excerptLength”

 *  [SRD75](https://wordpress.org/support/users/srd75/)
 * (@srd75)
 * [2 weeks ago](https://wordpress.org/support/topic/php-warning-undefined-array-key-excerptlength-3/)
 * Our site’s error_log is `20MB`, and full of the error:
 *     ```wp-block-code
       PHP Warning: Undefined array key "excerptLength" in /home/user/public_html/wp-includes/blocks/post-excerpt.php on line 47
       ```
   
 * Help appreciated.

Viewing 1 replies (of 1 total)

 *  Moderator [threadi](https://wordpress.org/support/users/threadi/)
 * (@threadi)
 * [2 weeks ago](https://wordpress.org/support/topic/php-warning-undefined-array-key-excerptlength-3/#post-18946684)
 * It seems as though something in your project is triggering the generation of 
   block excerpts with incomplete information. This could be caused by plugins you’re
   using or even your theme.
 * For example, are you using an excerpt block in your archives, and was it possibly
   provided by a plugin?
 * If you’re unsure, you can identify the cause by deactivating plugins one by one.
   Once you’ve found the plugin causing the issue, you should no longer see any 
   entries in the error log.

Viewing 1 replies (of 1 total)

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 * In: [Fixing WordPress](https://wordpress.org/support/forum/how-to-and-troubleshooting/)
 * 1 reply
 * 2 participants
 * Last reply from: [threadi](https://wordpress.org/support/users/threadi/)
 * Last activity: [2 weeks ago](https://wordpress.org/support/topic/php-warning-undefined-array-key-excerptlength-3/#post-18946684)
 * Status: not resolved

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