Title: PHP Notice: Function wp_cache_flush_runtime was called incorrectly. Last modified: December 1, 2022 --- # PHP Notice: Function wp_cache_flush_runtime was called incorrectly. * [CoPilot](https://wordpress.org/support/users/wordpressorgtimpeter/) * (@wordpressorgtimpeter) * [3 years, 6 months ago](https://wordpress.org/support/topic/php-notice-function-wp_cache_flush_runtime-was-called-incorrectly/) * Hi, * Thanks for the plugin! We just switched from the Memcached Redux plugin to yours, since yours seems to be better maintained. * There seems to be an issue though. Our debug.log gets flooded with the following message: * `[01-Dec-2022 20:48:03 UTC] PHP Notice: Function wp_cache_flush_runtime was called incorrectly. Your object cache implementation does not support flushing the in-memory runtime cache. Please see Debugging in WordPress for more information. (This message was added in version 6.1.0.) in /wp-includes/functions. php on line 5835` * Note. This message is new with 6.1 and the previous plugin had the same issue. * Any ideas? * Cheers, Tim Viewing 11 replies - 1 through 11 (of 11 total) * [Ben Andersen](https://wordpress.org/support/users/ben72/) * (@ben72) * [3 years, 6 months ago](https://wordpress.org/support/topic/php-notice-function-wp_cache_flush_runtime-was-called-incorrectly/#post-16253434) * [@wordpressorgtimpeter](https://wordpress.org/support/users/wordpressorgtimpeter/) I’m on LiteSpeed cache with REDIS and seeing the same thing. So it’s a more general issue it seems. * Plugin Contributor [Andrija Vučinić](https://wordpress.org/support/users/aidvu/) * (@aidvu) * [3 years, 6 months ago](https://wordpress.org/support/topic/php-notice-function-wp_cache_flush_runtime-was-called-incorrectly/#post-16266089) * Yeah, seems related to this [https://core.trac.wordpress.org/changeset/54448](https://core.trac.wordpress.org/changeset/54448). Will take a look in the coming weeks. * For now, you can probably just add: * ``` function wp_cache_supports( $feature ) { if ( $feature === 'flush_runtime' ) { return true; } return false; } ``` * [SimpleRick](https://wordpress.org/support/users/keramikoch/) * (@keramikoch) * [3 years, 6 months ago](https://wordpress.org/support/topic/php-notice-function-wp_cache_flush_runtime-was-called-incorrectly/#post-16269067) * We do have the same error * Thread Starter [CoPilot](https://wordpress.org/support/users/wordpressorgtimpeter/) * (@wordpressorgtimpeter) * [3 years, 5 months ago](https://wordpress.org/support/topic/php-notice-function-wp_cache_flush_runtime-was-called-incorrectly/#post-16289664) * Thank you for acknowledging [@aidvu](https://wordpress.org/support/users/aidvu/) Let’s hope you find a permanent solution soon. * [Ben Andersen](https://wordpress.org/support/users/ben72/) * (@ben72) * [3 years, 5 months ago](https://wordpress.org/support/topic/php-notice-function-wp_cache_flush_runtime-was-called-incorrectly/#post-16290160) * After updating to the latest LiteSpeed cache plugin I’m not seeing this in the logs any longer. * [kindking](https://wordpress.org/support/users/kindking/) * (@kindking) * [3 years, 3 months ago](https://wordpress.org/support/topic/php-notice-function-wp_cache_flush_runtime-was-called-incorrectly/#post-16504157) * I’m having same issue. Can somebody find out any solution. i don’t have installed any cache plugin. Just have woocommerce. * ```wp-block-code ErrorException User Notice: Function wp_cache_flush_runtime was called incorrectly. Your object cache implementation does not support flushing the in-memory runtime cache. Please see Debugging in WordPress for more information. (This message was added in version 6.1.0.) ``` * Plugin Contributor [Andrija Vučinić](https://wordpress.org/support/users/aidvu/) * (@aidvu) * [3 years, 3 months ago](https://wordpress.org/support/topic/php-notice-function-wp_cache_flush_runtime-was-called-incorrectly/#post-16517995) * [@kindking](https://wordpress.org/support/users/kindking/) try [https://wordpress.org/support/topic/php-notice-function-wp_cache_flush_runtime-was-called-incorrectly/#post-16266089](https://wordpress.org/support/topic/php-notice-function-wp_cache_flush_runtime-was-called-incorrectly/#post-16266089). Didn’t have time yet to fix. * [Gik000](https://wordpress.org/support/users/gik000/) * (@gik000) * [3 years, 2 months ago](https://wordpress.org/support/topic/php-notice-function-wp_cache_flush_runtime-was-called-incorrectly/#post-16549507) * Where should this function be added? * Plugin Contributor [Andrija Vučinić](https://wordpress.org/support/users/aidvu/) * (@aidvu) * [3 years, 2 months ago](https://wordpress.org/support/topic/php-notice-function-wp_cache_flush_runtime-was-called-incorrectly/#post-16555454) * > Where should this function be added? * Hey, in `object-cache.php`. * [bremnerr](https://wordpress.org/support/users/bremnerr/) * (@bremnerr) * [2 years, 11 months ago](https://wordpress.org/support/topic/php-notice-function-wp_cache_flush_runtime-was-called-incorrectly/#post-16840696) * Tried the above fix which resulted in the error: Cannot redeclare wp_cache_supports()( previously declared in /var/web/site/public_html/wp-includes/cache-compat.php: 198) * [ITP TECHNOLOGIE](https://wordpress.org/support/users/abitp/) * (@abitp) * [2 years, 11 months ago](https://wordpress.org/support/topic/php-notice-function-wp_cache_flush_runtime-was-called-incorrectly/#post-16892910) * same error Viewing 11 replies - 1 through 11 (of 11 total) The topic ‘PHP Notice: Function wp_cache_flush_runtime was called incorrectly.’ is closed to new replies. * ![](https://s.w.org/plugins/geopattern-icon/memcached.svg) * [Memcached Object Cache](https://wordpress.org/plugins/memcached/) * [Frequently Asked Questions](https://wordpress.org/plugins/memcached/#faq) * [Support Threads](https://wordpress.org/support/plugin/memcached/) * [Active Topics](https://wordpress.org/support/plugin/memcached/active/) * [Unresolved Topics](https://wordpress.org/support/plugin/memcached/unresolved/) * [Reviews](https://wordpress.org/support/plugin/memcached/reviews/) * 11 replies * 8 participants * Last reply from: [ITP TECHNOLOGIE](https://wordpress.org/support/users/abitp/) * Last activity: [2 years, 11 months ago](https://wordpress.org/support/topic/php-notice-function-wp_cache_flush_runtime-was-called-incorrectly/#post-16892910) * Status: not resolved