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InvalidSelectorException

The selector expression (CSS or XPath) is malformed and cannot be parsed by the browser.

Common Causes

  1. 1Syntax error in XPath expression (missing quotes, brackets)
  2. 2Invalid CSS selector syntax
  3. 3Selector contains unescaped special characters
  4. 4XPath expression uses browser-unsupported functions

How to Fix

Validate your selector in browser DevTools

// In browser console:
// For CSS:
document.querySelector('#my-element')

// For XPath:
document.evaluate('//div[@class="content"]', document, null, XPathResult.FIRST_ORDERED_NODE_TYPE, null).singleNodeValue

Test your selectors in browser DevTools before using them in Selenium.

How ObserveOne Helps

ObserveOne validates selectors at build time and warns about invalid or fragile selector expressions.

Start Monitoring Free

Related Errors

NoSuchElementException

No element matching the locator strategy could be found in the current page DOM. The element may not exist, may not have loaded yet, or the locator may be incorrect.

StaleElementReferenceException

The element previously located is no longer attached to the DOM. The page was refreshed, navigated, or the element was re-rendered by JavaScript.

ElementNotInteractableException

The element exists in the DOM but cannot be interacted with. It may be hidden, disabled, or covered by another element.

ElementClickInterceptedException

The click command could not be completed because another element would receive the click at the target coordinates. A different element is covering the target.

SessionNotCreatedException: Could not start a new session

WebDriver could not create a new browser session. Usually caused by a version mismatch between the browser and the driver.