Customer is unable to sign in to Copilot Chat.

• Copilot Chat Extension Version: 0.48.1

• VS Code Version: 1.126.0

• OS Version: Windows 11

• Feature (e.g. agent/edit/ask mode):

• Selected model (e.g. GPT 4.1, Claude 3.7 Sonnet): Claude Opus 4.6

• Logs:
  2026-05-27 12:27:27.920 [warning] GitHub login failed
  2026-05-27 12:27:29.462 [info] [CopilotCLIChatSessionContentProvider] listSessions took 68.51529999999912ms
  2026-05-27 12:27:29.911 [error] [GitServiceImpl][exec] git diff --raw --numstat --diff-filter=ADMR -z HEAD -- [277ms] Error: warning: in the working copy of '.gitignore', LF will be replaced by CRLF the next time Git touches it
  2026-05-27 12:27:29.912 [error] [GitServiceImpl][exec] git diff --raw --numstat --diff-filter=ADMR -z HEAD -- [277ms] Error: Failed to execute git command (git diff --raw --numstat --diff-filter=ADMR -z HEAD --). Error: warning: in the working copy of '.gitignore', LF will be replaced by CRLF the next time Git touches it
  2026-05-27 12:27:29.912 [error] [ClaudeWorkspaceFolderService] Error while processing workspace changes: Error: Failed to execute git command (git diff --raw --numstat --diff-filter=ADMR -z HEAD --). Error: Failed to execute git command (git diff --raw --numstat --diff-filter=ADMR -z HEAD --). Error: warning: in the working copy of '.gitignore', LF will be replaced by CRLF the next time Git touches it
  2026-05-27 12:27:30.414 [warning] GitHub login failed
  2026-05-27 12:27:30.418 [error] You are not signed in to GitHub. Please sign in to use Copilot.
  2026-05-27 12:27:31.014 [error] [GitServiceImpl][exec] git diff --raw --numstat --diff-filter=ADMR -z --merge-base release/20250604 -- [318ms] Error: warning: in the working copy of '.gitignore', LF will be replaced by CRLF the next time Git touches it
  2026-05-27 12:27:31.014 [error] [GitServiceImpl][exec] git diff --raw --numstat --diff-filter=ADMR -z --merge-base release/20250604 -- [318ms] Error: Failed to execute git command (git diff --raw --numstat --diff-filter=ADMR -z --merge-base release/20250604 --). Error: warning: in the working copy of '.gitignore', LF will be replaced by CRLF the next time Git touches it
  2026-05-27 12:27:31.014 [error] [ClaudeWorkspaceFolderService] Error while processing workspace changes: Error: Failed to execute git command (git diff --raw --numstat --diff-filter=ADMR -z --merge-base release/20250604 --). Error: Failed to execute git command (git diff --raw --numstat --diff-filter=ADMR -z --merge-base release/20250604 --). Error: warning: in the working copy of '.gitignore', LF will be replaced by CRLF the next time Git touches it
  2026-05-27 12:27:31.657 [error] [GitServiceImpl][exec] git diff --raw --numstat --diff-filter=ADMR -z --merge-base master -- [288ms] Error: warning: in the working copy of '.gitignore', LF will be replaced by CRLF the next time Git touches it
  2026-05-27 12:27:31.657 [error] [GitServiceImpl][exec] git diff --raw --numstat --diff-filter=ADMR -z --merge-base master -- [289ms] Error: Failed to execute git command (git diff --raw --numstat --diff-filter=ADMR -z --merge-base master --). Error: warning: in the working copy of '.gitignore', LF will be replaced by CRLF the next time Git touches it
  2026-05-27 12:27:31.657 [error] [ClaudeWorkspaceFolderService] Error while processing workspace changes: Error: Failed to execute git command (git diff --raw --numstat --diff-filter=ADMR -z --merge-base master --). Error: Failed to execute git command (git diff --raw --numstat --diff-filter=ADMR -z --merge-base master --). Error: warning: in the working copy of '.gitignore', LF will be replaced by CRLF the next time Git touches it
  Diagnostics :
  GitHub Copilot Chat

  Extension: 0.48.1 (prod)
  VS Code: 1.119.0 (8b640eef5a6c6089c029249d48efa5c99adf7d51)
  OS: win32 10.0.22631 x64
  GitHub Account: Signed Out

Network

User Settings:

"http.proxy": "our-company-proxy",
"http.systemCertificatesNode": true,
"github.copilot.advanced.debug.useElectronFetcher": true,
"github.copilot.advanced.debug.useNodeFetcher": false,
"github.copilot.advanced.debug.useNodeFetchFetcher": true

Connecting to https://api.github.com/:

DNS ipv4 Lookup: 140.82.121.5 (21 ms)
DNS ipv6 Lookup: Error (20 ms): getaddrinfo ENOTFOUND api.github.com
Proxy URL: our-company-proxy (3 ms)
Proxy Connection: 200 Connection established (338 ms)
Electron fetch (configured): HTTP 200 (244 ms)
Node.js https: HTTP 200 (265 ms)
Node.js fetch: HTTP 200 (226 ms)

Connecting to https://api.githubcopilot.com/_ping:

DNS ipv4 Lookup: 140.82.114.22 (20 ms)
DNS ipv6 Lookup: Error (27 ms): getaddrinfo ENOTFOUND api.githubcopilot.com
Proxy URL: (4 ms)
Proxy Connection: 200 Connection established (42 ms)
Electron fetch (configured): HTTP 200 (946 ms)
Node.js https: HTTP 200 (552 ms)
Node.js fetch: HTTP 200 (555 ms)

Connecting to https://copilot-proxy.githubusercontent.com/_ping:

DNS ipv4 Lookup: 20.250.119.64 (23 ms)
DNS ipv6 Lookup: Error (20 ms): getaddrinfo ENOTFOUND copilot-proxy.githubusercontent.com
Proxy URL: our-company-proxy (4 ms)
Proxy Connection: 200 Connection established (59 ms)
Electron fetch (configured): HTTP 200 (141 ms)
Node.js https: HTTP 200 (217 ms)
Node.js fetch: HTTP 200 (171 ms)

Connecting to https://mobile.events.data.microsoft.com/: HTTP 404 (408 ms)
Connecting to https://dc.services.visualstudio.com/: HTTP 404 (864 ms)
Connecting to https://copilot-telemetry.githubusercontent.com/_ping: HTTP 200 (631 ms)
Connecting to https://copilot-telemetry.githubusercontent.com/_ping: HTTP 200 (491 ms)
Connecting to https://default.exp-tas.com/: HTTP 400 (233 ms)

Number of system certificates: 145

Steps to Reproduce:

1. Click on Sign In button in VS Code