Title: Plugin Activation Issues – Multisite Critical Error Last modified: April 23, 2023 --- # Plugin Activation Issues – Multisite Critical Error * Resolved [nezdymenko](https://wordpress.org/support/users/nezdymenko/) * (@nezdymenko) * [2 years, 11 months ago](https://wordpress.org/support/topic/plugin-activation-issues-multisite-critical-error/) * Hello 10Web Team, I hope this message finds you well. I am reporting some issues I encountered after activating your plugin. I have a multisite WordPress website. After activation of your plugin, there is a Critical Error –**Deprecated: Return type of FacebookAds\Object\ServerSide\AdsPixelSettings::offsetExists($offset) should either be compatible with ArrayAccess::offsetExists(mixed $offset): bool, or the #[\ReturnTypeWillChange] attribute should be used to temporarily suppress the notice in /home/lassustandartsen/domains/lassustandartsen.nl/public_html/ wp-content/plugins/official-facebook-pixel/vendor/facebook/php-business-sdk/src/ FacebookAds/Object/ServerSide/AdsPixelSettings.php on line 154 Deprecated: Return type of FacebookAds\Object\ServerSide\AdsPixelSettings::offsetGet($offset) should either be compatible with ArrayAccess::offsetGet(mixed $offset): mixed, or the#[\ ReturnTypeWillChange] attribute should be used to temporarily suppress the notice in /home/lassustandartsen/domains/lassustandartsen.nl/public_html/wp-content/ plugins/official-facebook-pixel/vendor/facebook/php-business-sdk/src/FacebookAds/ Object/ServerSide/AdsPixelSettings.php on line 163 Deprecated: Return type of FacebookAds\Object\ServerSide\AdsPixelSettings::offsetSet($offset, $value) should either be compatible with ArrayAccess::offsetSet(mixed $offset, mixed $value): void, or the #[\ReturnTypeWillChange] attribute should be used to temporarily suppress the notice in /home/lassustandartsen/domains/lassustandartsen.nl/public_html/ wp-content/plugins/official-facebook-pixel/vendor/facebook/php-business-sdk/src/ FacebookAds/Object/ServerSide/AdsPixelSettings.php on line 173 Deprecated: Return type of FacebookAds\Object\ServerSide\AdsPixelSettings::offsetUnset($offset) should either be compatible with ArrayAccess::offsetUnset(mixed $offset): void, or the #[\ReturnTypeWillChange] attribute should be used to temporarily suppress the notice in /home/lassustandartsen/domains/lassustandartsen.nl/public_html/ wp-content/plugins/official-facebook-pixel/vendor/facebook/php-business-sdk/src/ FacebookAds/Object/ServerSide/AdsPixelSettings.php on line 186 Fatal error: Uncaught TypeError: call_user_func_array(): Argument #1 ($callback) must be a valid callback, class “\TenWebOptimizer\OptimizerAdmin” not found in /home/lassustandartsen/domains/ lassustandartsen.nl/public_html/wp-includes/class-wp-hook.php:308 Stack trace:# 0 /home/lassustandartsen/domains/lassustandartsen.nl/public_html/wp-includes/ class-wp-hook.php(332): WP_Hook->apply_filters() #1 /home/lassustandartsen/domains/ lassustandartsen.nl/public_html/wp-includes/plugin.php(517): WP_Hook->do_action()# 2 /home/lassustandartsen/domains/lassustandartsen.nl/public_html/wp-admin/admin- header.php(118): do_action() #3 /home/lassustandartsen/domains/lassustandartsen. nl/public_html/wp-admin/plugins.php(605): require_once(‘…’) #4 /home/lassustandartsen/ domains/lassustandartsen.nl/public_html/wp-admin/network/plugins.php(13): require(‘…’)# 5 {main} thrown in /home/lassustandartsen/domains/lassustandartsen.nl/public_html/ wp-includes/class-wp-hook.php on line 308** * After the deactivation of the Facebook Pixel plugin, there is another critical error –**Fatal error: Uncaught TypeError: call_user_func_array(): Argument #1( $callback) must be a valid callback, class “\TenWebOptimizer\OptimizerAdmin” not found in /home/lassustandartsen/domains/lassustandartsen.nl/public_html/wp- includes/class-wp-hook.php:308 Stack trace: #0 /home/lassustandartsen/domains/ lassustandartsen.nl/public_html/wp-includes/class-wp-hook.php(332): WP_Hook-> apply_filters() #1 /home/lassustandartsen/domains/lassustandartsen.nl/public_html/ wp-includes/plugin.php(517): WP_Hook->do_action() #2 /home/lassustandartsen/domains/ lassustandartsen.nl/public_html/wp-admin/admin-header.php(118): do_action() # 3 /home/lassustandartsen/domains/lassustandartsen.nl/public_html/wp-admin/plugins. php(605): require_once(‘…’) #4 /home/lassustandartsen/domains/lassustandartsen. nl/public_html/wp-admin/network/plugins.php(13): require(‘…’) #5 {main} thrown in /home/lassustandartsen/domains/lassustandartsen.nl/public_html/wp-includes/ class-wp-hook.php on line 308** * Could you please help me we that?Please guide how to resolve these issues. Your support would be greatly appreciated.Thank you in advance, and I look forward to hearing from you soon.Best regards, Viewing 2 replies - 1 through 2 (of 2 total) * Plugin Support [Mane Grigoryan](https://wordpress.org/support/users/manegr/) * (@manegr) * [2 years, 11 months ago](https://wordpress.org/support/topic/plugin-activation-issues-multisite-critical-error/#post-16685105) * Hi dear [@nezdymenko](https://wordpress.org/support/users/nezdymenko/) , Thank you for contacting us. * Unfortunately 10Web Booster is not developed for a multisite. Please, kindly don’t enable the plugin for a multisite. * We are sorry it did not work for you. You will not face issues if using the plugin with single websites. * Feel free to let us know in case you need further assistance. Regards, Mane * Thread Starter [nezdymenko](https://wordpress.org/support/users/nezdymenko/) * (@nezdymenko) * [2 years, 10 months ago](https://wordpress.org/support/topic/plugin-activation-issues-multisite-critical-error/#post-16767287) * Hi [@manegr](https://wordpress.org/support/users/manegr/) , Thank you for you reply. Hope you will add this in the future. Have a nice day. Viewing 2 replies - 1 through 2 (of 2 total) The topic ‘Plugin Activation Issues – Multisite Critical Error’ is closed to new replies. * ![](https://ps.w.org/tenweb-speed-optimizer/assets/icon-256x256.png?rev=2753401) * [10Web Booster - Website speed optimization, Cache & Page Speed optimizer](https://wordpress.org/plugins/tenweb-speed-optimizer/) * [Frequently Asked Questions](https://wordpress.org/plugins/tenweb-speed-optimizer/#faq) * [Support Threads](https://wordpress.org/support/plugin/tenweb-speed-optimizer/) * [Active Topics](https://wordpress.org/support/plugin/tenweb-speed-optimizer/active/) * [Unresolved Topics](https://wordpress.org/support/plugin/tenweb-speed-optimizer/unresolved/) * [Reviews](https://wordpress.org/support/plugin/tenweb-speed-optimizer/reviews/) ## Tags * [critical error](https://wordpress.org/support/topic-tag/critical-error/) * [multisite](https://wordpress.org/support/topic-tag/multisite/) * 2 replies * 2 participants * Last reply from: [nezdymenko](https://wordpress.org/support/users/nezdymenko/) * Last activity: [2 years, 10 months ago](https://wordpress.org/support/topic/plugin-activation-issues-multisite-critical-error/#post-16767287) * Status: resolved