Title: Undefined array key “default”
Last modified: November 17, 2025

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# Undefined array key “default”

 *  Resolved [ArcticFritid](https://wordpress.org/support/users/metuza/)
 * (@metuza)
 * [5 months, 3 weeks ago](https://wordpress.org/support/topic/undefined-array-key-default/)
 * Hello,
 * For the last 2-3 weeks i have found these warnings in my 2 sites. Found on POST
   and GET requests to cart, add-to-cart and checkout.
 * `FastCGI sent in stderr: "PHP message: PHP Warning: Undefined array key "default"
   in /www/public/wp-includes/class-wp-list-util.php on line 170" while reading 
   response header from upstream, client: 78.26.35.163, server: www.xxxxxxxx.no,
   request: "POST /?wc-ajax=sco_checkout_order HTTP/2.0"`
 * Warnings are only found in relation to cart, checkout, ajax add-to-cart and as
   above sco_checkout_order action.
 * As far as i can see Svea plugin and my theme is the only updates i have done 
   during this period so just wondering if the above warning could be related to
   Svea plugin?
 * Brgds
   Rune

Viewing 1 replies (of 1 total)

 *  Thread Starter [ArcticFritid](https://wordpress.org/support/users/metuza/)
 * (@metuza)
 * [5 months, 3 weeks ago](https://wordpress.org/support/topic/undefined-array-key-default/#post-18722252)
 * After further testing i have found that warning is still there after deactivating
   Svea. I then belive it is related to my theme in use.
 * Brgds
   Rune

Viewing 1 replies (of 1 total)

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 * ![](https://ps.w.org/svea-checkout-for-woocommerce/assets/icon-128x128.gif?rev
   =2728301)
 * [Svea Checkout for WooCommerce](https://wordpress.org/plugins/svea-checkout-for-woocommerce/)
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 * 1 reply
 * 1 participant
 * Last reply from: [ArcticFritid](https://wordpress.org/support/users/metuza/)
 * Last activity: [5 months, 3 weeks ago](https://wordpress.org/support/topic/undefined-array-key-default/#post-18722252)
 * Status: resolved