Troubleshooting of selenium errors

The printable version is no longer supported and may have rendering errors. Please update your browser bookmarks and please use the default browser print function instead.

SeleniumHQ Browser Automation (php-webdriver/php-webdriver: PHP client for Selenium/WebDriver protocol. Previously facebook/php-webdriver)

How to tracking the selenium errors

Checking the standalone selenium server is running or not ps aux | grep selenium on Linux
Checking the log file of standalone selenium server e.g. launching the server by the command sudo nohup java -jar selenium-server-standalone-3.141.59.jar > /home/user/selenium.log 2>&1 &. The log file was located at /home/user/selenium.log
(optional) Checking the port where the selenium server is running e.g. wget http://localhost:4444
Checking the error log file of HTTP server e.g. sudo tail /var/log/nginx/error.log
(optional) Checking the error log file of PHP-FPM defined in the configuration file /etc/php-fpm.d/www.conf

How to resolve Uncaught Facebook\WebDriver\Exception\InvalidSelectorException

Error message

PHP Fatal error:  Uncaught Facebook\WebDriver\Exception\InvalidSelectorException: invalid selector: The result of the xpath expression "xxx" is: [object Attr]. It should be an element.
  (Session info: chrome=83.0.4103.61) in /path/to/vendor/php-webdriver/webdriver/lib/Exception/WebDriverException.php:105

Situation

After the term was keyed in into the text box, the script shuld auto click the specified button which specified by XPath expression.

Possibile soultions

Solution1: Using headless chrome^[1]
Solution2: Not click the button which specified by XPath expression. Send the ENTER to submit the form^[2].

How to resolve [WARNING]: This version of ChromeDriver only supports Chrome version xx or [WARNING]: This version of ChromeDriver has not been tested with Chrome version 86

Situation

Download the same version of ChromeDriver with the version installed on the computer or server
You may need to stop the ChromeDriver in the process list if you could not overwrite the existing ChromeDriver file
- Win (1) keyin cmd to open the command prompt with the administrative permission (2) and keyin taskkill /IM "chromedriver.exe" /F to stop the ChromeDriver process
- Linux
Overwrite the existing ChromeDriver file