PHP Fatal error: Uncaught TypeError

Hello,

we use the LS-Cache Version 7.7 and when we try to duplicate a product on our eshop with a the Duplicate Page plugin, WordPress crashes with a critical error and debug log shows the following error:

[19-Feb-2026 16:43:47 UTC] PHP Fatal error:  Uncaught TypeError: Automattic\WooCommerce\Internal\Caches\VersionStringGenerator::delete_version(): Return value must be of type bool, null returned in  /home/wordpress/public_html/wp-content/plugins/woocommerce/src/Internal/Caches/VersionStringGenerator.php:155
Stack trace:
#0  /home/wordpress/public_html/wp-content/plugins/woocommerce/src/Internal/Caches/ProductVersionStringInvalidator.php(602): Automattic\WooCommerce\Internal\Caches\VersionStringGenerator->delete_version()
#1  /home/wordpress/public_html/wp-content/plugins/woocommerce/includes/data-stores/class-wc-product-variable-data-store-cpt.php(759): Automattic\WooCommerce\Internal\Caches\ProductVersionStringInvalidator->invalidate()
#2  /home/wordpress/public_html/wp-content/plugins/woocommerce/includes/class-wc-data-store.php(224): WC_Product_Variable_Data_Store_CPT->sync_variation_names()
#3  /home/wordpress/public_html/wp-content/plugins/woocommerce/includes/class-wc-product-variable.php(532): WC_Data_Store->__call()
#4  /home/wordpress/public_html/wp-content/plugins/woocommerce/includes/abstracts/abstract-wc-product.php(1507): WC_Product_Variable->after_data_store_save_or_update()
#5  /home/wordpress/public_html/wp-content/plugins/woocommerce/includes/admin/class-wc-admin-duplicate-product.php(189): WC_Product->save()
#6  /home/wordpress/public_html/wp-content/plugins/woocommerce/includes/admin/class-wc-admin-duplicate-product.php(116): WC_Admin_Duplicate_Product->product_duplicate()
#7  /home/wordpress/public_html/wp-includes/class-wp-hook.php(341): WC_Admin_Duplicate_Product->duplicate_product_action()
#8  /home/wordpress/public_html/wp-includes/class-wp-hook.php(365): WP_Hook->apply_filters()
#9  /home/wordpress/public_html/wp-includes/plugin.php(522): WP_Hook->do_action()
#10  /home/wordpress/public_html/wp-admin/admin.php(424): do_action()
#11  /home/wordpress/public_html/wp-admin/edit.php(10): require_once(' /home/wordpress/...')
#12 {main}
  thrown in  /home/wordpress/public_html/wp-content/plugins/woocommerce/src/Internal/Caches/VersionStringGenerator.php on line 155

For debugging the issue, we disabled all other plugins except WooCommerce, the duplicate page plugin (for testing) and LS-Cache and the crit. error still occurred. The only way to fix that crit. error sofar, is renaming the object-cache.php to object-cache.php.bak. Disabling the Object Cache in the LS Cache Settings page did not solve the issue as well.

Regards,

JT

The page I need help with: [log in to see the link]