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How to fix Teredo/Multiplayer Issues. ( IPSEC: 0x00000000 & ALERT: Unable to Join Session. )

By tofu🍓

ALERT: Unable to Join Session. / IPSEC: 0x00000000 Possible Fixes.

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Created by

tofu🍓
Online

Category: Multiplayer

Languages: English

Posted

Updated

1 Jul, 2021 @ 7:19am

3 Jan, 2022 @ 2:19pm

2,942	Unique Visitors
74	Current Favorites

Guide Index

Overview

Prologue & Disclaimer

Possible Fix #1 | Easiest

Possible Fix #2 | What worked for me

Possible Fix #3 | Teredo & IP Helper

Possible Fix #4 | For People with Antivirus like BitDefender

That's all folks.

Comments

Prologue & Disclaimer

The Problem:

The Goal:
Collect all possible fixes that will allow you to finally enjoy the multiplayer feature of Forza Horizon 4.

Disclaimer!

Although this guide aims to find and collect all the possible fixes. There is a possibility that nothing on this guide will work for you.

This guide will not go through the first main troubleshoot fixes such as
Flushing your DNS
Changing your DNS to another ( Google / Cloudfare )
Resetting your Router settings.
ipconfig /release & ipconfig /renew.
Blocking IPv6
Opening Ports
Re-Installing the game
Re-Installing network drivers (like Teredo )
and the list goes on and on.

This guide will focus on the most common and one uncommon fix(es) that worked for me.

Good Luck.

Possible Fix #1 | Easiest

This is the easiest possible fix and there is a strong possibility that It will work for you. As I have seen from many community discussions.

If you get no Error Code on your Network Diagnostics message it is very likely that you only need to just re-login from the Menu as shown below:
Thanks to Hank for the image

How to re-login:
Start the game as usual

Sign out ( Your game will need to restart )

Sign back in with your credentials.

(works? wow you are lucky, if not.. there is still hope)

Possible Fix #2 | What worked for me

After watching countless Youtube videos and Following online guides the last fix I tried was to Disable National Instruments from msconfig.

National Instruments drivers comes with Virtual Instrumentation software ( Multisim Circuit Simulator). If you have never installed such Program this might not exist on your computer but you don't lose anything to search for it.

Step 1: Press the Windows Key & R at the same time ( Open the Run menu )

Step 2: Type msconfig and press Ok.

Step 3: Go on the Services tab.

Step 4: Find and Disable any National Instruments Software.
[ Tip: Sort by Manufacturer to find everything easier and sorted ]

Remember to Restart your Computer.

Possible Fix #3 | Teredo & IP Helper

Teredo / Teredo Drivers / Teredo Service is used to connect to the multiplayer features on Forza Horizon 4 and so it's required to be able to connect and play multiplayer.

In your quest to fix the Teredo Drivers you might have stumbled upon the Xbox Networking tab on the Windows Settings. Surprisingly enough,this is not an indication of your Forza Horizon 4 Multiplayer functions working or not.

As you can see I get the message that "Teredo is unable to qualify." and that my Server connectivity is "Blocked." but multiplayer works for me as it should. I have no idea why it is designed like this.

There is also this way to fix Teredo Driver Problem. Check it out!

Moving on...

Microsoft provides us with the all the important troubleshooting which I have linked below of this section as Xbox Networking Troubleshooting. It goes greatly in depth and it's the best and most trustworthy collection for the Teredo Driver & IP Helper information you can find.

Xbox Networking Troubleshooting. [support.xbox.com]

You will need to open CMD ( Command Prompt ) with Administrator Priviledges to input the commands.

In the search box on the taskbar, type cmd, and then choose the Run as Administrator Option

In Solutions that require the Services tab you will need to open the taskbar and type in
In the search box "services".

Possible Fix #4 | For People with Antivirus like BitDefender

If you use bitdefender it's very likely that it's going to interfere with the multiplayer aspect of the game and you will need to add the game as an exception on the BitDefender Firewall/
Gif Showing the Steps we will be following ( instead of text )
On the Bitdefender Interface find the Protection tab ( Left side of the Application )
Find the Advanced Threat Defense & Click on Manage Exceptions
Click " ADD AN EXCEPTION "
Drag & drop the file/folder you want to exclude inside the search bar or under Exceptions options. Or click the magnifying glass to find and select the file/folder you want to exclude.
Click OK. & Make sure all these checkboxes are selected:

• On-access scan (Real-time protection against malware. Bitdefender automatically scans all accessed files and e-mails).

• On-demand scan (Manual, user-performed scans.)

• Embedded scripts. (The ability to scan different applications for scripts that might harm your device).
Lastly, Click ADD EXCEPTION to save the changes and close the window.
You can add everything related to Forza Horizon as an exception just to be safe. You should have an exception list like this ( But with 1 Exception if you don't add everything ).

! ! !
You might need to disable the Bitdefender Firewall in order for the fix to work right.

Experiment with it in order to find what works for your setup.

Thanks to Hank for the help on this section! Adding this whole section wouldn't be possible without his help.

Source[www.bitdefender.com]

That's all folks.

Remember after trying each Solution to Restart your Computer. This is very important.
Anything important I missed? Anything you want to see added? Drop a comment below!

If nothing worked for you in the end shoot a friend request my way and we might be able to figure something out.

Steam

11 Comments

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Pelmeshka223 22 Jan, 2024 @ 2:41am

Thank you a lot! Never thought that NI software can be a problem for FH4's online

Cha Koibito 23 Apr, 2023 @ 8:29am

Thanks for help! Just relogin and it works =__=

socialist distancing ☭ 1 Apr, 2023 @ 10:44am

You're a lifesaver, I never would've thought National Instruments Labview was stopping me from getting online in Forza Horizon, but it absolutely was. That's a hell of an issue to diagnose.
First my 3DConnexion pad was stopping controllers from working in Sekiro, now NI Labview was stopping me from playing Forza. Moral of the story—engineering software is incompatible with fun.

Super Crisp 18 Oct, 2022 @ 6:00pm

OMFG!! Thankyou, i spent ages watching videos off yt to fix teredo and a bunch of stuff... none of them worked. Turns out all i had to do was sign out and back in again lol... bruh wtf, anyway thx
so much

JimineyBob 2 Aug, 2022 @ 11:01am

I have spent over a year without multiplayer and gave up on fixing it months ago. I did all the hard stuff. Online articles, youtube videos, resetting IPs... No answers. Over a year later, I see this guide and say, "Why not?"

Fix #1 worked. I just had to sign in.
Thanks, I hate myself.

aabo 27 Jul, 2021 @ 3:24am

Thank youuuu!<3

Spynxies 9 Jul, 2021 @ 8:21pm

i have an i3 9100f an rx570 and 16 gbs of ram. i was able to play the game before at 1440p with barely any stutter. after past few updates game has been pretty unplayable. tried doing the recommended settings on fh4 but seem to have done nothing. updated all drivers and nothing has changed. ive tried looking on youtube as well and only found videos of the online problem. might just be the recent updates for fh4. hopefully they will fix.

tofu🍓 [author] 9 Jul, 2021 @ 3:14am

(1/2)
Before I am going to add my thoughts I want to add that even on my PC which is above the recommended specs for the game ( 1070 , 24gb ram , i5 8600K ) I myself also get occasional stutters when I am on Multiplayer.

It's either because of my Internet lagging for a second or because it's just how the Steam version of Forza is and it just has to stutter for some odd reason. Although it doesn't ruin the experience for me you are probably guaranteed to get occasional stutters now and again.

Now;
Do you know the specifications of your comptuer? As in CPU , GPU , How much RAM you have , etc. If it's a laptop it might stutter because it's overheating.If it's also a laptop and you use wi-fi it might be because of using wi-fi (which will make your internet very slow compared to a stable ethernet cable connection ).Your Internet connection might be slow enough for the game to not be able to process multiplayer fast enough.

tofu🍓 [author] 9 Jul, 2021 @ 3:14am

(2/2)

It also might be because there is not enough space on your hard drive. It could be many many things. but you can start from here:

If you are not sure if your PC is powerful try to lower the video settings from the options and go from there.

Apparently from my research it's a common thing for the Steam Port. Some people suggest turning on Vsync from the Options but I haven't found any guaranteed fix. Try to experiment with your video settings and tell me how it goes

Good luck

Spynxies 8 Jul, 2021 @ 8:32pm

fix #1 worked for me but the game is unplayable for me it stutters too much. do you know why or can you help?

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