Title: Undefined array key 1 in common.php
Last modified: August 21, 2025

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# Undefined array key 1 in common.php

 *  Resolved [Mike Meinz](https://wordpress.org/support/users/mikemeinz/)
 * (@mikemeinz)
 * [8 months ago](https://wordpress.org/support/topic/undefined-array-key-1-in-common-php/)
 * The PHP error_log contains a lot of the “Undefined array key” PHP warning message.
   Sometimes dozens per second. This has been going on for quite some time. I just
   started working on this site and the first entry in the error_log is this PHP
   Warning and that was from June, 2025. June might have been when the last admin
   deleted the error_log file. There are no error_logs archived for me to review
   to see if the problem started even earlier.
 * `PHP Warning: Undefined array key 1 in /home/eltownhall/public_html/wp-content/
   plugins/relevanssi/lib/common.php on line 1834`
 * I uninstalled (and deleted) Relevanssi and did a new install. The warnings re-
   occurred.
 * Search works.
 * Relevanssi Version: 4.24.6
   WordPress Version 6.8.2PHP Version 8.3
 * Please let me know if there is anything that I can do to resolve this issue. 
   
   Thank you for all of your efforts with the Relevanssi PlugIn.
 * The page I need help with: _[[log in](https://login.wordpress.org/?redirect_to=https%3A%2F%2Fwordpress.org%2Fsupport%2Ftopic%2Fundefined-array-key-1-in-common-php%2F%3Foutput_format%3Dmd&locale=en_US)
   to see the link]_

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

 *  Plugin Author [Mikko Saari](https://wordpress.org/support/users/msaari/)
 * (@msaari)
 * [8 months ago](https://wordpress.org/support/topic/undefined-array-key-1-in-common-php/#post-18608161)
 * Sounds like you have a malformed synonym. All synonym entries should be “a=b”,
   but I’m guessing you have something that doesn’t have a “=” in it.
 *  Thread Starter [Mike Meinz](https://wordpress.org/support/users/mikemeinz/)
 * (@mikemeinz)
 * [8 months ago](https://wordpress.org/support/topic/undefined-array-key-1-in-common-php/#post-18608227)
 * You are correct! Thank you so much!!!
   I copied my synonym list to an Excel spreadsheet
   and used Text to Columns with delimiter of =. Immediately, I saw the problem.
   One entry had a – instead of an =. Same key on the U.S. Keyboard!

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

The topic ‘Undefined array key 1 in common.php’ is closed to new replies.

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## Tags

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

 * 2 replies
 * 2 participants
 * Last reply from: [Mike Meinz](https://wordpress.org/support/users/mikemeinz/)
 * Last activity: [8 months ago](https://wordpress.org/support/topic/undefined-array-key-1-in-common-php/#post-18608227)
 * Status: resolved