Fatal Error after installing cleaverreach-Plugin

After installing the latest version of the Cleaverreach-WP-Plugin I get a fatal error when clicking the WP-Backend-main-navigation-item “Cleaverreach”. Message showing in WP-debug-mode:

Fatal error: Uncaught Error: Call to undefined function CleverReach\WordPress\IntegrationCore\Infrastructure\Utility\getmypid() in /var/web/staging/public_html/wp-content/plugins/cleverreach-wp/vendor/cleverreach/integration-core/src/Infrastructure/Utility/GuidProvider.php:22 Stack trace: #0 /var/web/staging/public_html/wp-content/plugins/cleverreach-wp/vendor/cleverreach/integration-core/src/Infrastructure/TaskExecution/TaskRunnerWakeup.php(103): CleverReach\WordPress\IntegrationCore\Infrastructure\Utility\GuidProvider->generateGuid() #1 /var/web/staging/public_html/wp-content/plugins/cleverreach-wp/vendor/cleverreach/integration-core/src/Infrastructure/TaskExecution/TaskRunnerWakeup.php(55): CleverReach\WordPress\IntegrationCore\Infrastructure\TaskExecution\TaskRunnerWakeup->doWakeup() #2 /var/web/staging/public_html/wp-content/plugins/cleverreach-wp/Components/Utility/class-task-queue.php(76): CleverReach\WordPress\IntegrationCore\Infrastructure\TaskExecution\TaskRunnerWakeup->wakeup() #3 /var/web/staging/public_html/wp-content/plugins/cleverreach-wp/Controllers/class-clever-reach-frontend-controller.php(95): CleverReach\WordPress\Components\Utility\Task_Queue::wakeup() #4 /var/web/staging/public_html/wp-includes/class-wp-hook.php(324): CleverReach\WordPress\Controllers\Clever_Reach_Frontend_Controller->render(”) #5 /var/web/staging/public_html/wp-includes/class-wp-hook.php(348): WP_Hook->apply_filters(”, Array) #6 /var/web/staging/public_html/wp-includes/plugin.php(517): WP_Hook->do_action(Array) #7 /var/web/staging/public_html/wp-admin/admin.php(259): do_action(‘toplevel_page_w…’) #8 {main} thrown in /var/web/staging/public_html/wp-content/plugins/cleverreach-wp/vendor/cleverreach/integration-core/src/Infrastructure/Utility/GuidProvider.php on line 22

I moved the site to a staging-server and I deactivated all other plugins and changed to theme twenty-twenty-three for debugging, but the fatal-error stayed. Website is running on PhP 8.2, changing to 8.3 and 8.5 don’t helped either. I’m not a PhP-programmer so I got no ideas how to fix this problem.