How to Fix Helldivers 2 Unable to Establish Connection to Game

• Check the server condition: Visit the official Helldivers website from time to time. Check out any notification or announcement on the game's social media channels due to server failure or while undergoing maintenance. There is no point in wasting time to fix a problem when it is on the server end.

• Close the recording software: It can be closed for the moment because the software itself, say GeForce Experience, might cause interference with multiplayer connections. Run the game without recording to verify if that resolves the issue.

• Relaunch the game: A lot of times, a simple relaunch works if the connection problem was temporary or in the case of an SLI miscommunication.
• Disable IPv6: It sometimes does not play nice with some games. To verify if this is true, at your network settings:
• 1. Press the Windows key, then input Network and Sharing Center.
• 2. Click Change adapter settings.
• 3. Right-click on your connection to the network.
• 4. Properties.
• 5. Remove the check next to Internet Protocol Version 6 (TCP/IPv6) > OK.
• Disable crossplay: The function of crossplay messes up a lot of connections. This is in case the servers of the other platforms are problematic. To just eliminate the crossplay setting, visit game settings.

• VPN: A VPN removes all sorts of connection limits or even fixes a pervasively weak Internet connection. Make use of a highly reliable VPN service and configure it to the latter as dictated by the selected provider.
• Change of ISP: In the case of continuous issues, consider either switching the internet service provider or its type, or simply changing the mode of connection mobile hotspots, Wi-Fi, and Ethernet modes. That will have most cases isolating the problem to your current network setup.

• Verify the files: to make sure the files remain intact in the sense that the game files were never corrupted. That is doable through the game launcher or platform: Steam, Epic Games Store, Origin.
• Try to restart your device : At times, all that is required is to reinitialize the network configurations on your system through a reboot.
• Verify network support: Ascertain if your internet is working, with a stable connection. It would be recommendable to check the speed or even try to bring up online services to determine if the problem is bound to Helldivers 2.
• Router firmware upgrade: Outdated firmware on the router may cause problems with the connections. 

Check for any current release updates and download.

• Port Forwarding: Improves stability when connecting, especially with NAT issues, by forwarding some ports. Search on the internet for guidelines or the documentation for your router on how to do port forwarding with regard to Helldivers 2.
• Contact Support: If all the above troubleshooting did not help, contact Helldivers 2 customer support for additional guidance; they might have specific tips on troubleshooting or know of issues with the servers.