Fix VPN Client Connection Issue

My VPN client refuses to establish a connection and immediately throws the “Server not found” error whenever I try. Slow speeds or random drop-outs would be one thing, but at the moment I can’t connect at all.

I need someone who can dig into the configuration, logs, certificates and routing on both the client and the server side, pinpoint why the tunnel never forms, and apply a clean fix so the VPN signs in reliably every time. Please bring experience with common VPN protocols, certificate chains, DNS and firewall rules—whatever it takes to make the “Server not found” message disappear for good—then document the changes you make so I can maintain the setup afterward.