Can firewall settings or network configurations lead to 'curl error code 52' for FiveM, and how can I verify this?

Yes, firewalls are a very common cause. While a firewall might permit the initial outgoing connection from FiveM, it could block the incoming 'reply' even if it's just an empty response. To verify: 1. Temporarily disable your server's/client's firewall. 2. If using a cloud server, check the associated security groups or network ACLs to ensure both outbound and inbound traffic on relevant ports (usually 80, 443) is allowed. 3. Use `traceroute` or `telnet` from your server to the specific remote IP/port that FiveM is trying to reach to test basic network path and connectivity.