Title: Error with PHP8 Last modified: February 4, 2021 --- # Error with PHP8 * Resolved [jaeger](https://wordpress.org/support/users/jaegerschnitzel/) * (@jaegerschnitzel) * [5 years, 4 months ago](https://wordpress.org/support/topic/error-with-php8/) * Today I tried to update to PHP8. Unfortunately my blog does not work. I activated Debug mode and saw the following error: * Fatal error: Uncaught Error: Call to undefined function create_function() in / data/web/htdocs/wp-content/plugins/wp-memory-usage/wp-memory-usage.php:108 Stack trace: #0 /data/web/htdocs/wp-settings.php(388): include_once() #1 /data/web/ htdocs/wp-config.php(37): require_once(‘/data/web/…’) #2 /data/web/htdocs/wp- load.php(37): require_once(‘/data/web/…’) #3 /data/web/htdocs/wp-admin/admin. php(34): require_once(‘/data/web/…’) #4 /data/web/htdocs/wp-admin/index.php(10): require_once(‘/data/web/…’) #5 {main} thrown in /data/web/htdocs/wp-content/plugins/ wp-memory-usage/wp-memory-usage.php on line 108 * Perhaps you can fix it. I hope so 🙂 - This topic was modified 5 years, 4 months ago by [jaeger](https://wordpress.org/support/users/jaegerschnitzel/). Viewing 7 replies - 1 through 7 (of 7 total) * Plugin Author [sminozzi](https://wordpress.org/support/users/sminozzi/) * (@sminozzi) * [5 years, 4 months ago](https://wordpress.org/support/topic/error-with-php8/#post-14000893) * Hi Jaeger, * This error message is caused by another plugin, not for our plugin. * Try to deactivate this plugin: WP-Memory-Usage because it was actualized last time 7 years ago and is compatible with WordPress 3.7, not 5.6. * Please, try our plugin wp-memory and let us know if it has some issue with PHP 8 and we will fix it quickly, if necessary. [https://wordpress.org/plugins/wp-memory/](https://wordpress.org/plugins/wp-memory/) * Our plugin can show you the available memory too. * To deactivate it, remove this folder: /data/web/htdocs/wp-content/plugins/wp- memory-usage/ * You can do it by FTP or thru your file manager on your hosting panel. * You can also change your php to 7.x and do it, go to your Dashboard => Plugins => WP-Memory-Usage and deactivate it. * Otherwise, request support to your hosting company to remove that folder. * Cheers, Bill * Thread Starter [jaeger](https://wordpress.org/support/users/jaegerschnitzel/) * (@jaegerschnitzel) * [5 years, 4 months ago](https://wordpress.org/support/topic/error-with-php8/#post-14004869) * I’m very sorry about the confusion. Yes you are correct. And thanks a lot for the explanation how I can fix the problem. * Unfortunately your plugin also throws and error: * > Fatal error: Uncaught Error: Call to undefined function add_management_page() > in /data/htdocs/wp-content/plugins/wp-memory/wpmemory.php:180 Stack trace: # > 0 /data/htdocs/wp-includes/class-wp-hook.php(287): wp_memory_init(”) #1 /data/ > htdocs/wp-includes/class-wp-hook.php(311): WP_Hook->apply_filters(NULL, Array)# > 2 /data/htdocs/wp-includes/plugin.php(484): WP_Hook->do_action(Array) #3 /data/ > htdocs/wp-settings.php(579): do_action(‘wp_loaded’) #4 /data/htdocs/wp-config. > php(37): require_once(‘/data/web/…’) #5 /data/htdocs/wp-load.php(37): require_once(‘/ > data/web/…’) #6 /data/htdocs/wp-admin/admin.php(34): require_once(‘/data/web/…’)# > 7 /data/htdocs/wp-admin/plugins.php(10): require_once(‘/data/web/…’) #8 {main} > thrown in /data/htdocs/wp-content/plugins/wp-memory/wpmemory.php on line 180 * Plugin Author [sminozzi](https://wordpress.org/support/users/sminozzi/) * (@sminozzi) * [5 years, 4 months ago](https://wordpress.org/support/topic/error-with-php8/#post-14005096) * Hi Jaeger, * Thanks for let me know. I’m on London timezone. Tomorrow I will find a solution and let you know. I will install PHP 8 in our server and run a couple of tests. * Thanks for the patience, Cheers, Bill * Plugin Author [sminozzi](https://wordpress.org/support/users/sminozzi/) * (@sminozzi) * [5 years, 4 months ago](https://wordpress.org/support/topic/error-with-php8/#post-14007473) * Hi Jaeger, * I’m working on that. Please, check if you are running the last version of WordPress( 5.6 or 5.6.1) * Please, let me know. Cheers, Bill * Plugin Author [sminozzi](https://wordpress.org/support/users/sminozzi/) * (@sminozzi) * [5 years, 4 months ago](https://wordpress.org/support/topic/error-with-php8/#post-14007789) * Hi Jaeger, * The plugin **works fine now** (Version 1.4) with PHP 8 (tested with PHP 8.0.1) Just install from WordPress the version 1.4 * Thanks for the patience and for the collaboration. * Cheers, Bill * Thread Starter [jaeger](https://wordpress.org/support/users/jaegerschnitzel/) * (@jaegerschnitzel) * [5 years, 4 months ago](https://wordpress.org/support/topic/error-with-php8/#post-14007916) * Thanks a lot for that quick fix! I can agree that it’s working now 🙂 * Plugin Author [sminozzi](https://wordpress.org/support/users/sminozzi/) * (@sminozzi) * [5 years, 4 months ago](https://wordpress.org/support/topic/error-with-php8/#post-14007926) * Hi Jaeger, You are welcome. I’m happy to hear that. Please, leave us a good review. Thanks, Bill Viewing 7 replies - 1 through 7 (of 7 total) The topic ‘Error with PHP8’ is closed to new replies. * ![](https://s.w.org/plugins/geopattern-icon/wp-memory_402b42.svg) * [Memory Usage, Memory Limit, PHP and Server Memory Health Check and Provide Suggestions](https://wordpress.org/plugins/wp-memory/) * [Frequently Asked Questions](https://wordpress.org/plugins/wp-memory/#faq) * [Support Threads](https://wordpress.org/support/plugin/wp-memory/) * [Active Topics](https://wordpress.org/support/plugin/wp-memory/active/) * [Unresolved Topics](https://wordpress.org/support/plugin/wp-memory/unresolved/) * [Reviews](https://wordpress.org/support/plugin/wp-memory/reviews/) * 7 replies * 2 participants * Last reply from: [sminozzi](https://wordpress.org/support/users/sminozzi/) * Last activity: [5 years, 4 months ago](https://wordpress.org/support/topic/error-with-php8/#post-14007926) * Status: resolved