Reached error page: about:neterror when trying to navigate to other tabs if there is a form submit under that tab

Question

when I use Selenium to do automation testing, I hit an issue, here are all scenarios:

There are several tabs on top of the page, now that I want to click those tabs and fill up all forms under those tabs, but if I submit formA which under tabA, then I can not navigate to other tabs automatically. If I didn't submit the form data, the issue will not be happened. Here is the log:

1513753361368 Marionette DEBUG Received DOM event "beforeunload" for "https://192.168.1.20/link.cgi?1513753343333"
1513753361388 Marionette DEBUG Received DOM event "beforeunload" for "https://192.168.1.20/link.cgi?1513753343333"
1513753361391 Marionette DEBUG Received DOM event "pagehide" for "https://192.168.1.20/link.cgi?1513753343333"
1513753361391 Marionette DEBUG Received DOM event "unload" for "https://192.168.1.20/link.cgi?1513753343333"
1513753361427 Marionette DEBUG Received DOM event "DOMContentLoaded" for "about:neterror?e=connectionFailure&u=https%3A//192.168.1.20/network.cgi&c=UTF-8&f=regular&d=Firefox%20%E6%97%A0%E6%B3%95%E5%BB%BA%E7%AB%8B%E5%88%B0%20192.168.1.20%20%E6%9C%8D%E5%8A%A1%E5%99%A8%E7%9A%84%E8%BF%9E%E6%8E%A5%E3%80%82"
org.openqa.selenium.WebDriverException: Reached error page: about:neterror?e=connectionFailure&u=https%3A//192.168.1.20/network.cgi&c=UTF-8&f=regular&d=Firefox%20%E6%97%A0%E6%B3%95%E5%BB%BA%E7%AB%8B%E5%88%B0%20192.168.1.20%20%E6%9C%8D%E5%8A%A1%E5%99%A8%E7%9A%84%E8%BF%9E%E6%8E%A5%E3%80%82
Build info: version: '3.8.1', revision: '6e95a6684b', time: '2017-12-01T18:33:54.468Z'
System info: host: 'PC-20161127KZEG', ip: '192.168.131.1', os.name: 'Windows 7', os.arch: 'amd64', os.version: '6.1', java.version: '1.8.0_111'
Driver info: org.openqa.selenium.firefox.FirefoxDriver
Capabilities {acceptInsecureCerts: true, browserName: firefox, browserVersion: 57.0.2, javascriptEnabled: true, moz:accessibilityChecks: false, moz:headless: false, moz:processID: 42248, moz:profile: C:\Users\Administrator\AppD..., moz:webdriverClick: false, pageLoadStrategy: normal, platform: XP, platformName: XP, platformVersion: 6.1, rotatable: false, timeouts: {implicit: 0, pageLoad: 300000, script: 30000}}

Solution

This error message...

org.openqa.selenium.WebDriverException: Reached error page: about:neterror?e=connectionFailure&u=https%3A//192.168.1.20/network.cgi&c=UTF-8&f=regular&d=Firefox%20%E6%97%A0%E6%B3%95%E5%BB%BA%E7%AB%8B%E5%88%B0%20192.168.1.20%20%E6%9C%8D%E5%8A%A1%E5%99%A8%E7%9A%84%E8%BF%9E%E6%8E%A5%E3%80%82

...implies that there was a Network Error while initializing a WebDriver / Web Browsing session.

However, the main issue is, in case of these Network Errors for a valid and absolute URL it is expected for the WebDriver instance i.e. the driver to return a value of Success with a value of null, as per the updated Go Command Spec. WebDriver should return Error with error code unknown error.

This issue is still pending with Selenium Team through Issue#4475 which will be addressed by GeckoDriver Team through Issue#770 which depends on the Mozilla Issue ID#1312679