Diving in Halo 3Campaign with an online friend (or more) sometimes simply does not work … on PC. You send in the invitations and group, pick and load a mission, and then the game suddenly hangs before you kick to the main screen. Or you can play for a short while, and then everything freezes and boots you.
Either way, you are torn apart and may even lose your progress, both of which are annoying as hell. And this experience is not isolated to Halo 3—It can happen to other Microsoft games that rely on Xbox Live multiplayer servers as well, whether it’s the rest of Master Chief Collection or Force.
The problem is usually related to Network Address Translation (NAT) and Windows 10’s Teredo service. As a network issue, it can be a bit difficult to resolve, as the causes of the problem vary from person to person. To help, we’ve gathered all the most important troubleshooting steps you can take (and have had to try us) to resolve the issue.
How to fix Halo 3 campaign cooperative connection problems
To sum it up, Xbox Live servers handle multiplayer connections for Halo: Master Chief Collection (even on PC), and if you are not connected to them with an open NAT type, it may hinder the quality of your multiplayer experience or directly block co-op games.
So your ideal end goal when you go through these troubleshooting steps is to achieve open NAT while connected to the servers. Moderate NAT can work just as well under certain circumstances (see below), so do not look if your router will not work.
- Open NAT: Can connect to users with all NAT types
- Moderate NAT: Can connect to users with moderate and open NAT
- Strict NAT: Can only connect to users with open NAT
(Anecdotally, we have had the most consistent success with moderate NAT when the rest of the party had open NAT.)
Step 1: Find out your Xbox Live connection status
First, determine the exact type of problem by getting an Xbox Live connection report in Windows 10 settings.
Go to Settings> Games> Game mode> Xbox network (or enter “game mode” in Windows Search), then wait for the screen to report your Xbox Live multiplayer settings.
Most people with this Halo: Master Chief Collection co-op connectivity issues will initially see a screen saying that Teredo cannot qualify and that you may be blocked from playing multiplayer games. A small group also sees a message stating that the server connection is blocked.
Step 2: Let Windows try to fix it
Windows 10 can sometimes solve the problem. Click the same Xbox Networking screen Fix it button. Wait until it reports that it tried to resolve the issue, and then click Check again button.
The lucky ones will see an updated report showing an open NAT and a connection to the Xbox Live servers. Try campaign collaboration again; it should now be successful, provided your party has the same attitudes.
Note: For some people, this step is just a temporary fix. You may need to do this before each planned session with campaign collaboration.
Step 3: Additional troubleshooting
However, step 2 does not always fix the problem on its own – even if you perform a reboot suggested by Windows. You have to dive a little deeper.
The various solutions have a fairly wide range, so we have started with proposals that are simpler or more often clear up the problem and ramp up to those who are more involved. After trying a solution, restart and then try steps 1 and 2 again before proceeding to the next proposal.
- Under your date and time settings, select “Set time automatically” and then click the “Sync now” button. (Some services may crash when there is no time lag between your computer and a server.)
- Activate Windows Firewall.
- Make sure you do not have any personal or corporate VPN services blocking access to Xbox Live ports.
- Verify that your antivirus or firewall software is not blocking the specific ports needed to connect to Xbox Live. Look for the settings that assign permissions to incoming and outgoing ports.
- Set up manual port forwarding on your router or combo modem / router device for the ports needed to connect to Xbox Live. (You can also enable UPnP [Universal Plug and Play] on your router, but it has more security risks.) Some routers are much more accommodating than others, so you may need to look in your manual or find tips from other users on Google to find out how to do this. After completing this step, cycle your router and then follow with a restart of your computer.
- Right-click the Start menu icon on the taskbar, and then open it Windows PowerShell (Admin) Enter the following commands:
netsh int teredo set state disable
netsh int teredo set state type=default
netsh int teredo set state enterpriseclient
netsh int teredo set state servername=teredo.remlab.net
- Make sure your settings match those described at the bottom of page 1 of this Microsoft Forum post.
- Also try restarting all four services mentioned.
- Disable network connections that you do not use in the Network and Sharing Center section of the control panel – for example, if you use Wi-Fi, disable Ethernet.
- To re-enable later, navigate to the same window, click the “Change adapter settings” link, and then right-click the connection to find the option.
- Check to see if any other programs may be causing a conflict with your Xbox Live server connection – for example, a “Game Mode” in one could cause a port routing conflict. To narrow down the list of potential problem makers, review which programs you have installed and determine which ones are actively using or managing network ports.