Halo Master Chief Collection: Diving into the Halo 3 campaign with a friend online sometimes just… doesn’t work on PC. You will send out invitations and choose a mission, but then the game will crash abruptly before returning to the main screen. Or you can play for a short period of time before the block.
This experience isn’t isolated to Halo 3 – it can happen with other Microsoft games that rely on Xbox Live servers for multiplayer, like with Forza. The problem is typically related to network address translation (NAT) and the Windows 10 Teredo service.
As a network problem, it can be a bit nebulous to fix, as the reasons for the problem vary from person to person. To help you, we have compiled all the main steps you can take.
How to fix Halo Master 3 campaign co-op connection issues
To sum up the matter, Xbox Live servers handle multiplayer connections for Halo: Master Chief Collection (even on PC) and if you connect to them with a closed NAT type, the quality of the multiplayer experience will be hampered or a total blocking of the cooperative play.
So our ultimate goal will be to get an open NAT when we connect to the servers. Moderate NAT can work under certain circumstances, so don’t despair if your router won’t cooperate.
- Open NAT : can connect to users with any NAT type
- Moderate NAT : Can connect to users with moderate and open NAT
- Closed NAT – Can only connect to users with open NAT
Step 1: Find out your Xbox Live connectivity status
First determine the exact nature of the problem by getting an Xbox Live Connectivity Report in Windows 10 settings.
Let’s go to Settings > Game > Game Mode > Xbox Networking (or type “game mode” in Windows Search), then wait for the screen to display Xbox Live multiplayer settings.
Most people with this Halo Master Chief Collection cooperative connectivity issue will initially see a screen that says: Teredo is unable to qualify and that you may be stuck in multiplayer games. A smaller group will also see a message saying server connectivity is blocked.
Step 2: Let Windows try to fix it
Windows 10 can sometimes fix the problem on its own. On the same Xbox Networking screen , we click on the Resolve button. We wait for the resolution, then click the Check button again.
If we’re lucky we’ll see an updated report showing an open NAT and a connection to Xbox Live servers. Try the co-op campaign, it should now be successful provided your group has the same settings.
Step 3: Further troubleshooting
Unfortunately, step 2 doesn’t always fix the problem, even when you do a reboot as suggested by Windows. Let’s see other methods that unblock the connection:
- Under the Date and Time settings, select “Set Time Automatically”, then click the “ Synchronize Now ” button. (Some services may stop when there is a time mismatch between the PC and a server.)
- Enable Windows Firewall.
- Disable any personal or corporate VPN services that block access to Xbox Live ports.
- Confirm that your anti-virus or firewall software is not blocking the specific ports required to connect to Xbox Live. Then look for settings that assign permissions to inbound and outbound ports.
- Set up manual port forwarding on your router or modem for the ports needed to connect to Xbox Live. (You can also enable UPnP [Universal Plug and Play] on your router, but it presents a greater security risk.) Some routers are much more accommodating than others, so you may need to consult the manual or find suggestions on Google based on your exact template. After completing this step, turn the router off and on again, then follow with a PC restart.
Right-click the Start menu icon in the taskbar, then open Windows PowerShell (Admin) and 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
Verify that the settings match those described at the bottom of page 1 in this Microsoft community forum post . Also try to restart each of the four services mentioned.
In the Network and Sharing Center part of the Control Panel, disable all network connections you are not using, for example, if you are using Wi-Fi, disable Ethernet.
Check to see if other programs might be creating a conflict with your Xbox Live server connection, such as a “Game Mode” activated by some software you installed.