Halo: CE Co-op "Connection Interrupted" *FIX

[RESSESPUFFS]

For starters since the moment I tried to play co-op with a friend we kept getting the fatal connection interrupted message and we would be booted out in the load screen to the first mission. We were able to play online multiplayer and even a bit of Reach co-op but that gave us some problems as well.

This is was worked for me, thank god: I noticed that my friend did not have the "Gaming" setting (Start > Settings > Gaming) but I did. 343 keep saying this open NAT thing, but it shouldn't be done to your router because that will cause security issues, rather I believe it's meant for Windows OS. Within the Gaming setting, there's "Xbox Networking" on the left panel, once in there it will search for NAT type and the server. 10/10 times when I first open it it always says "Teredo is unable to qualify." After hitting "Check Again," it will search again and then say "Open," this is what you want. Someone suggested it, so that's how I ended up there. The kicker was that my friend, who had the same exact Windows build as me (1903) did not have that "Gaming" setting available within his settings. I found that if you download the "media feature pack" (https://www.microsoft.com/en-us/software-download/mediafeaturepack) for your build it will then allow the "Gaming" setting to be available.

I had my friend open the setting then the xbox networking, check again, once his NAT type said open with that networking window, we loaded into the game first try for the first time ever, no problem. If you still can't see the "Gaming" setting, this guy proposes a little fix, though I have no clue if it actually works, but it did for him: https://www.f0il.com/fix-windows-10-1903-gaming-missing-from-settings/

Once again, this is what worked for me, and it's because co-op utilizes a host connection (peer to peer) and if both systems aren't NAT open than there will be issues. I struggled for days, trust me, so frustrated because I hyped it to my friend, but finally our struggle is over. I hope this will help some.

EDIT: Once you have "Checked Again," and the NAT type is "Open," do NOT close the window because then you'll have to reestablish the open network again. For whatever reason every time you exit out of Xbox Networking by closing the window, when you open it back up the error "Teredo is unable to qualify" will appear again making you repeat the check again process. So just keep it open once you've established an Open NAT type.

[Commander Raymond]

I had my friend do this, but his NAT is set to Strict, how do i help him change it to open

[Felix]

Doesn't work

[Commander Raymond]

Originally posted by Felix:

Doesn't work

we where able to open the NAT type, it worked for us.

[RESSESPUFFS]

Originally posted by Felix:

Doesn't work

A suggestion, you have to keep the Xbox Networking window open, because when I close it after checking again, it will always say "unable to qualify," once I open it back up. So keep the window open once you hit "Check Again," and the NAT type says Open. That goes for both parties.

For whatever reason it did take a couple of tries once we established the open network, but worked in the end.

[tenkday]

My friend ran into this, and changing the graphics settings to classic graphics fixed it apparently

[RESSESPUFFS]

Oh nice, and then you can switch back?