我不明白為什么我會(huì)收到此錯(cuò)誤：raise exception_class(message, screen, stacktrace) selenium.common.exceptions.StaleElementReferenceException: Message: The element reference of <a id="u153-popover-trigger--3926" class="udlite-custom-focus-visible browse-course-card--link--3KIkQ" href="/course/kafka-streams-real-time-stream-processing-master-class/"> is stale; either the element is no longer attached to the DOM, it is not in the current frame context, or the document has been refreshed我使用 WebDriverWait 兩次來(lái)檢查是否加載了新頁(yè)面：如果新頁(yè)面的分頁(yè)鏈接發(fā)生相應(yīng)變化如果新頁(yè)面的課程列表div元素被加載  from selenium import webdriver    from selenium.webdriver.common.keys import Keys    from selenium.webdriver.firefox.options import Options    from selenium.webdriver.common.by import By    from selenium.webdriver.support.ui import WebDriverWait    from selenium.webdriver.support import expected_conditions as EC    from selenium.common.exceptions import TimeoutException        def waitForLoad(inputXPath):         Wait = WebDriverWait(driver, 10)        Wait.until(EC.presence_of_element_located((By.XPATH, inputXPath)))        options = Options()    options.headless = True    driver = webdriver.Firefox(options=options, service_log_path='NUL')        driver.get("https://www.udemy.com/courses/development/?sort=highest-rated")        courses = []    f = open("0udemy.txt","a", encoding="utf-8")    page = 1        try:        waitForLoad("//div[@class='filter-panel--paginated-course-list--2F0x1']")    except TimeoutException as e:        print("timeout!")        while True:        ## I also tried that :         #courses = driver.find_elements_by_xpath("//div[@class='course-list--container--3zXPS']//a[contains(@class, 'browse-course-card--link--3KIkQ')]")        #for i in courses:        #    f.write(f"{i.get_attribute('href')}\n")我在第 20 頁(yè)和第 80 頁(yè)之間收到陳舊錯(cuò)誤。我的世界紀(jì)錄是第 78 頁(yè)。