Fatal error: Uncaught Error: Class 'WP_Background_Process' not found in D:\www\wordpress - 安裝環境+外掛測試\02.外掛程式\常用外掛\perfmatters\inc\classes\DatabaseOptimizationProcess.php:4 Stack trace: #0 {main} thrown in D:\www\wordpress - 安裝環境+外掛測試\02.外掛程式\常用外掛\perfmatters\inc\classes\DatabaseOptimizationProcess.php on line 4