When playing an online game, you are likely to encounter network errors from time to time. Since this is also true for MW3, I will explain all the ways to fix the networking failed to start error below.
How to solve the MW3 networking error
As the name suggests, the networking failed to start error in MW3 occurs when your game is unable to connect to the Activision servers. This error may be on your end, or it could be on the server's side. Before you begin, make sure to check the Activision Server Status page to resolve this issue.
Related: How to fix MW3 Niamey Logan ‘Data is Corrupt’ error
If the servers are operational, you can take the following steps to troubleshoot this error:
- Restart your router.
- As most internet connections nowadays use dynamic IP addresses, any issues you may be facing can be resolved with this simple step.
- Restart your PC.
- Ensure your PC and Windows is up-to-date.
- Check Windows Updates and your PC manufacturer's website to ensure this.
- Disconnect from any VPNs you may be using
- Some VPNs are blacklisted by websites and services.
- Create a Firewall exception.
- Open the start menu, and search Allow an app through Windows Firewall, click change settings and find the game, then check off both boxes.
- Verify your game file integrity.
- Depending on which platform you own the game on, go into the library, choose the game, and go into its settings to redownload or recheck the game files.
If none of these steps resolve the issue for you, I highly recommend contacting Activision Support, as you may have been subject to a ban or blacklist. You should also inform them of all the steps you have already taken to try to resolve this issue.
For more on MW3, be sure to check out How to unlock all vests in MW3 and MW3 & Warzone The Boys event challenges and rewards here on Pro Game Guides.