When you have errors in a execution of webdriver, and for some reason appears a message told that selenium is closed and your selenium doesn’t really closed.
Put this code for initialize the execution:
String Servidor = “http://127.0.0.1:4444/wd/hub“;
DesiredCapabilities capabilities = DesiredCapabilities.internetExplorer();
WebDriver driver = new RemoteWebDriver(new URL(Servidor),capabilities);
This way you will execute the test in your local machine and force this.