Port 443, Firewalls and SSL Certificates

Your firewall may be blocking Helldivers from connecting to the Campaign Backend. Make sure that any firewall in use is allowing Helldivers to perform outbound connections on port 443. Both inbound and outbound exceptions have to contain HELLDIVERS.

You might also have to make sure that the firewall is not rejecting self-signed SSL certificates, as this is what the Campaign Backend uses. Outbound rules regarding Helldivers and TCP port 443 have the action set to "Allow the connection", as "Allow the connection if it is secure" will reject the SSL certificate used by the Campaign Backend.

You can test it by going to https://api.helldiversgame.com/1.0/ from your computer. You should be given a warning that your connection is not private, secure, or similar. If you simply can't reach the site, either your router or ISP is blocking the traffic, probably due to the use of self signed certificates.