Fixing the 'GitHub Copilot Could Not Connect to Server' Error in VS Code

The ProblemIt usually happens right when you're in the flow. You're halfway through a complex function, but the ghost text stops appearing. You glance at the status bar and see the GitHub Copilot icon has turned red. A notification confirms the frustration: GitHub Copilot could not connect to server.

This error isn't a bug in the AI itself. Instead, it's a breakdown in the 'plumbing' between your local machine and GitHub’s API. If you are working on a corporate network using a VPN, a firewall, or an SSL inspection tool like Zscaler, your connection is likely being intercepted or blocked.

How to Debug the ConnectionDon't waste time reinstalling the extension yet. First, we need to see exactly why the handshake is failing. Most connection drops leave a specific trail in the logs.

1. Inspect the Output LogsPress Ctrl+Shift+U (or Cmd+Shift+U on Mac) to open the Output panel. Select GitHub Copilot from the dropdown menu. You are looking for these specific diagnostic codes:

• ECONNRESET: A firewall or proxy forcibly closed the connection.- ETIMEDOUT: The request timed out, usually meaning a gateway is silently dropping packets.- self signed certificate in certificate chain: Your company is using SSL inspection, and Copilot doesn't trust their local certificate.- 407 Proxy Authentication Required: Your proxy is stopping the request because it needs your credentials.### 2. Verify Network ReachabilityCheck if your machine can talk to the Copilot gateway at all. Open your terminal and run this command:

curl -I https://copilot-proxy.githubusercontent.com/_ping

A healthy connection returns an HTTP/2 200. If you get a 403 error or a 'Could not resolve host' message, the block is happening at the network level, not inside VS Code.

Proven Solutions### Solution 1: Manual Proxy ConfigurationVS Code tries to inherit proxy settings from your OS, but it often fails to pass them to the Copilot extension. You can force the connection by explicitly defining your proxy in settings.json.

{
  "http.proxy": "http://username:password@proxy.yourcompany.com:8080",
  "http.proxyStrictSSL": true,
  "http.proxySupport": "on"
}

If your office uses a transparent proxy that doesn't require a login, try setting "http.proxySupport": "fallback" instead.

Solution 2: Fix SSL Certificate ErrorsMany corporate networks use 'Man-in-the-Middle' (MITM) proxies to scan encrypted traffic. Since Copilot runs on Node.js, it ignores the Windows or macOS system certificate store by default.

The fast (less secure) way: Set "http.proxyStrictSSL": false in your VS Code settings. This stops Copilot from verifying the SSL chain. The professional way: Point Node.js to your company's Root CA certificate. Export your corporate certificate as a .pem file and set an environment variable:

# Windows (PowerShell)
$env:NODE_EXTRA_CA_CERTS="C:\Users\Admin\Certs\CompanyCA.pem"

# macOS/Linux
export NODE_EXTRA_CA_CERTS="/Users/name/certs/CompanyCA.pem"

Solution 3: Refresh Your TokenSometimes the connection is fine, but your session has expired. This is common if you haven't used the IDE in a few days.

• Click the Accounts icon in the bottom-left corner.- Sign out of your GitHub account.- Restart VS Code entirely.- Click the Copilot icon and sign back in.### Solution 4: Firewall Rules for IT AdminsIf you have access to the network firewall, or need to send a request to your IT department, ensure these four endpoints are whitelisted on Port 443:
• github.com- api.github.com- copilot-proxy.githubusercontent.com- origin-tracker.githubusercontent.com## Confirming the FixAfter applying these changes, verify the status with these three checks:
• Status Icon: The Copilot icon should be solid (white, blue, or gray) without a red 'X'.- Ghost Text: Open a new .js or .py file and type // calculate days between two dates. Suggestions should appear within 1.5 seconds.- Ping Check: The Output log should now show: [fetcher] Successfully reached https://copilot-proxy.githubusercontent.com/_ping.## SummaryConnection errors are rarely about the AI code. They are almost always about how your local Node.js environment handles network security. By properly configuring NODE_EXTRA_CA_CERTS or explicitly defining your http.proxy, you can resolve nearly 95% of these connectivity issues. Keep your extension updated to the latest version, as GitHub frequently pushes patches for better proxy handling.