Hello there. If you're struggling from not getting connected to the horizon life sessions and tried everyfix in youtube and serveral other websites? Then, this guide is guide is just for you.
First of all, try logging out and logging in again on the home screen. It might fix your problem 99%. Still doesn't work? Please do proceed through the guide. I bought this game like 8 months ago on Steam. For the first two months, multiplayer worked perfectly. After that, I was constantly receiving the ipsec error. Even I tried several yt videos and websites. Didn't worked for me. Finally i founded a fix. Hope this works for you as well. :)

Not wasting any time now. Lets get straight to the fix.

1. Turn off your antivirus:-

Forza horizon 4 needs some TCP/UDP ports to be opened to get connected to the Horizon Life session. Your antivirus might be blocking Forza horizon 4 to access those ports. So it's the first step, to disable your antivirus. I didn't said how to do that because each and everyone use different anti-virus. For instance, I use k7 antivirus. I just have to right-click the icon and click disable protection. If you're using Norton or Kaspersky it might be different scenario for you. So please do check about that with your antivirus provider.

2. Changing the DNS address:-

Next step would be we'll be setting the IPv4 & IPv6's DNS manually. To do that

1. Click "Windows Key" => type "control" and open control panel.
   
2. Select "Network & Internet" => then "Network and Sharing Center" => then on the left select "Change adapter settings".
   
3. Select the connection i.e by which way your PC/laptop is connected to internet. It might be ethernet or Wi-Fi.
   
4. After selecting it, right-click on the connection and select properties.
   
5. Make sure checkboxes of "Internet Protocol Version (TCP/IPv4)" & "Internet Protocol Version (TCP/IPv6)" are checked.
   
6. Click "Internet Protocol Version (TCP/IPv4)" and select "Properties" button.
   
7. It will be like this(below image) as default for you.
   
   
8. Click on "Use the following DNS Server addressess" and enter the following DNS values
   
   Preferred DNS Server

   8.8.8.8

   Alternate DNS Server

   8.8.4.4
9. After entering those values, the dialouge box should be like this. Then click "Ok".
   

Now that we've alternated the DNS for IPv4. We're going to do the same for IPv6.

1. Click "Internet Protocol Version (TCP/IPv6)" and select "Properties" button.
   
2. Click on "Use the following DNS Server addressess" and enter the following DNS values
   
   Preferred DNS Server

   2001:4860:4860::8888

   Alternate DNS Server

   2001:4860:4860::8844
3. After entering those values, the dialouge box should be like this. Then click "Ok".
   
   
4. Then click "Close" and close other control panel tabs as well.

Now all you have to do is restart your PC/Laptop and restart your router.
A simple turning off and turning on the router would work. Make sure your antivirus isn't enabled after you restarted your PC/Laptop. Then launch your game. Voila! You're in Horizon Live Session!!!

Now I've once reinstalled Forza Horizon 4 again, I got a popup from my antivirus when I launched the game. Like, Forza Horizon 4 is trying to access the internet with TCP/UDP connections. Once I clicked yes, after that I was able to play without disabling my antivirus. This guide helped me to fix the multiplayer issue I had for nearly 6 months. Hope this helps you as well. Do let me know in the comments if this works for you or not :).

If you have issues still, feel free to connect me through my discord.

• thevortexalpha#9738

Thank you and have a good day : )