Sign in fails

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GitHub Copilot plugin version

GitHub Copilot 0.14.0.202601160448_nightly com.microsoft.copilot.eclipse.feature.feature.group GitHub Copilot

Eclipse IDE and version

2025-12 (4.38.0)

Platform

When trying to sign in to GitHub Copilot from the Eclipse plugin, the login process fails and it is not possible to sign in.

Steps to reproduce

Steps to reproduce:

From the GitHub Copilot plugin in Eclipse, click on Sign in.

A window opens asking to open the GitHub login page and enter a verification code.

Click to open the browser and enter the verification code on the GitHub page.

The verification in the browser completes successfully.

However, nothing happens in Eclipse after the successful verification, and the user is not signed in.

Logs (optional)

Sign in failed: org.eclipse.lsp4j.jsonrpc.ResponseErrorException: Could not log in with device flow on https://github.com/: self-signed certificate in certificate chain

Expected behavior

sign in

Actual behavior

Sign in failed: org.eclipse.lsp4j.jsonrpc.ResponseErrorException: Could not log in with device flow on https://github.com/: self-signed certificate in certificate chain

Additional information

No response

Start at the Eclipse plugin's Sign in action and device-flow request, reproducing the failure with the reported plugin and Eclipse versions. Use the reported self-signed certificate error as the initial investigation point. Done means the browser verification completes and Eclipse signs the user in successfully, with the failure covered by an appropriate regression check.