Interactive Troubleshooter

Published: Sep 3, 2026

GitHub Copilot Not Suggesting Code: Diagnostic Guide

Time: 15 mins Level: Beginner

By StepDiag Engineering Team

Reviewed by Ibraheem Taofeeq Opeyemi

An interactive, step-by-step diagnostic guide to troubleshoot and resolve GitHub Copilot inline suggestion failures, auto-completion freezes, and extension connectivity errors in VS Code and JetBrains IDEs.

Full Diagnostic Tree & Step-by-Step Overview

Which Integrated Development Environment (IDE) is experiencing GitHub Copilot completion failures?

Visual Studio Code or VSCodium
JetBrains IDEs (IntelliJ IDEA, PyCharm, WebStorm) or Visual Studio

What indicator status or behavior are you observing in VS Code?

The Copilot status bar icon shows a red warning badge, strike-through icon, or authentication prompt.
The Copilot status bar icon appears active/normal, but no ghost text or suggestions appear while typing.

Fix Authentication Failures & Revoked OAuth Tokens in VS Code

Solution:

Root Cause: Expired OAuth Authentication Session or Invalid License Seat

When the GitHub Copilot status bar icon displays an error state or persistent sign-in prompts, your local OAuth authentication token has expired, been revoked, or is unlinked from an active GitHub Copilot Individual/Business seat.

Step-by-Step Fix:

1.Verify Service Health & Seat Assignment:

Check the GitHub Status Page to confirm there are no active platform outages affecting Copilot API endpoints.

Verify that your GitHub account has an active active subscription or organization license assignment.

2.Sign Out and Clear GitHub Accounts in VS Code:

Click the Accounts gear icon in the bottom-left corner of VS Code.

Select your GitHub account and click Sign Out.

Run the command palette (Ctrl + Shift + P or Cmd + Shift + P), type Developer: Reload Window, and press Enter.

3.Re-authenticate GitHub Copilot:

Click the Accounts icon again and select Sign in with GitHub to use GitHub Copilot.

Authorize the VS Code GitHub Copilot extension in your web browser and return to the editor.

Enable VS Code Inline Suggestions & Check Language Associations

Solution:

Root Cause: Disabled Inline Completion Settings or Language Disablement

If the status bar shows Copilot as active but ghost text fails to appear, inline completions may be disabled globally in editor settings, or Copilot has been disabled for the specific file extension / language mode.

Step-by-Step Fix:

1.Verify Global Inline Suggestion Setting:

Open VS Code Settings (Ctrl + , or Cmd + ,).

Search for editor.inlineSuggest.enabled and ensure the checkbox is Checked (true).

2.Check Copilot Language-Specific Status:

Open a file where completions are missing.

Click the GitHub Copilot icon in the bottom status bar.

Ensure Disable Completion for [Language] is NOT selected. If disabled, click Enable Completion for [Language].

3.Test Manual Trigger Shortcut:

Place your cursor inside an active file and press Alt + \ (Windows/Linux) or Option + \ (macOS) to manually force a completion fetch request.

If suggestions still fail, refer to the GitHub Official Documentation for advanced keybinding diagnostic steps.

What primary error condition is occurring in your IDE?

Persistent plugin sign-in loop, credential error, or device code authentication failure.
Network connection timeouts, SSL certificate rejection, or enterprise HTTP proxy errors.

Reset JetBrains / Visual Studio Copilot Plugin Credentials

Solution:

Root Cause: Corrupted Local Secure Storage or Token Keyring Mismatch

When IDE updates occur, the cached OAuth token stored in the operating system's native keychain (such as Windows Credential Manager or macOS Keychain) can become desynchronized from the GitHub Copilot plugin state.

Step-by-Step Fix:

1.Log Out from the Plugin Interface:

In JetBrains IDEs, navigate to Tools > GitHub Copilot > Log out of GitHub.

In Visual Studio, go to Tools > Options > GitHub > Copilot and sign out.

2.Purge Cached Plugin Settings:

Close the IDE completely.

Delete the Copilot configuration folder located in your user home directory:

Windows: %APPDATA%\GitHub Copilot

macOS/Linux: ~/.config/github-copilot

3.Re-authenticate via Device Code:

Relaunch the IDE and select Tools > GitHub Copilot > Login to GitHub.

Copy the device verification code presented by the IDE, paste it into the browser authorization page, and grant access.

Configure HTTP Proxy & Custom CA Certificates for Copilot

Solution:

Root Cause: Enterprise SSL Inspection or HTTP Proxy Blocking WebSocket Endpoints

Corporate firewalls utilizing Man-in-the-Middle (MITM) SSL inspection often break the secure TLS/WSS connections required by GitHub Copilot streams, leading to silent network dropouts.

Step-by-Step Fix:

1.Configure Editor Proxy Settings:

Set your corporate HTTP/HTTPS proxy URL in your IDE settings under Appearance & Behavior > System Settings > HTTP Proxy.

2.Configure Copilot SSL Strictness:

In VS Code or JetBrains settings, locate GitHub Copilot > HTTP.

Set github.copilot.advanced settings to allow custom CA certificates, or set http.proxyStrictSSL to false if using self-signed proxy inspection certificates.

3.Verify Endpoint Accessibility:

Ensure your network permits outbound HTTPS traffic to https://api.github.com and https://copilot-proxy.githubusercontent.com.

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