您必須清除「 自動過濾成人內容 」描述檔及和所有網頁過濾的描述檔，然後Safari瀏覽歷史記錄中的“清除”按鈕將可用。
How to show "Clear" in Safari Browsing History?
You have to uninstall Auto Filter Adult Content profile and all web filtering profiles, then the Clear button in the Safari Browsing History will be available.