Используйте следующие xpath
для идентификации элемента Button.
//button[@class='btn ow-btn-primary btn-block-xs pull-right' and contains(.,'Log On')]
Induce WebDriverWait
и elementToBeClickable
()
WebDriverWait wait = new WebDriverWait(driver, 10);
WebElement element=wait.until(ExpectedConditions.elementToBeClickable(By.xpath("//button[@class='btn ow-btn-primary btn-block-xs pull-right' and contains(.,'Log On')]")));
element.click();