Title: PHP Warning: Undefined array key 1
Last modified: January 17, 2026

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# PHP Warning: Undefined array key 1

 *  [pstretch](https://wordpress.org/support/users/pstretch/)
 * (@pstretch)
 * [4 months, 3 weeks ago](https://wordpress.org/support/topic/php-warning-undefined-array-key-1-3/)
 * I’m seeing this PHP warning repeating regularly in the error.log:
 *     ```wp-block-code
       PHP Warning:  Undefined array key 1 in /home/warescou/public_html/wp-content/plugins/wp-store-locator/frontend/class-frontend.php on line 1521
       ```
   
 * This relates to the map marker png images in \wpsl-markers\, which I’ve had issues
   with in my child theme (see my previous post here).
 * Any suggestions how to fix this, or should I ignore it?
 * Thank you

Viewing 5 replies - 1 through 5 (of 5 total)

 *  [farroyo](https://wordpress.org/support/users/farroyob/)
 * (@farroyob)
 * [4 months, 2 weeks ago](https://wordpress.org/support/topic/php-warning-undefined-array-key-1-3/#post-18791926)
 * Hi again,
 * Does this issue still persist after moving all the image files and code customizations
   to the child theme, as suggested in my previous ticket? Let us know.
 *  Thread Starter [pstretch](https://wordpress.org/support/users/pstretch/)
 * (@pstretch)
 * [4 months, 2 weeks ago](https://wordpress.org/support/topic/php-warning-undefined-array-key-1-3/#post-18791941)
 * There are no code modifications in the child theme relevant to WP Store Locator.
   Yes, the PHP warnings are seen after duplicating the \wpsl-markers\ directory
   into the child theme.
 *  [farroyo](https://wordpress.org/support/users/farroyob/)
 * (@farroyob)
 * [4 months, 2 weeks ago](https://wordpress.org/support/topic/php-warning-undefined-array-key-1-3/#post-18791954)
 * Hi again,
 * In WP Store Locator v2.2.261, that specific line is where the plugin generates
   the filenames for the @2x retina markers.
 * The error suggests there might be a file in your markers folder with an unexpected
   name or a missing extension. Could you please let us know the contents of your/
   wpsl-markers directory? A list of the filenames or a screenshot would be very
   helpful to pinpoint which one is causing the conflict.
 * Best regards,
 *  Thread Starter [pstretch](https://wordpress.org/support/users/pstretch/)
 * (@pstretch)
 * [4 months, 2 weeks ago](https://wordpress.org/support/topic/php-warning-undefined-array-key-1-3/#post-18792113)
 * This is the /wpsl-markers/ directory in the child theme:
 * ![](https://i0.wp.com/i.postimg.cc/FRqyYStn/screenshot.png?ssl=1)
 *  [farroyo](https://wordpress.org/support/users/farroyob/)
 * (@farroyob)
 * [4 months, 2 weeks ago](https://wordpress.org/support/topic/php-warning-undefined-array-key-1-3/#post-18796532)
 * Hi again, thanks for getting back.
 * Your map markers look good, I honestly don’t understand why that warning is showing
   up. In any case it is just a warning, if you can see the markers in the backend
   and the frontend I wouldn’t worry too much about it…

Viewing 5 replies - 1 through 5 (of 5 total)

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## Tags

 * [PHP Warning](https://wordpress.org/support/topic-tag/php-warning/)

 * 5 replies
 * 2 participants
 * Last reply from: [farroyo](https://wordpress.org/support/users/farroyob/)
 * Last activity: [4 months, 2 weeks ago](https://wordpress.org/support/topic/php-warning-undefined-array-key-1-3/#post-18796532)
 * Status: not resolved