Codex suddenly stopped working for me

What version of Codex CLI is running?

codex-cli 0.121.0

What subscription do you have?

Plus

Which model were you using?

gpt-5.4 xhigh

What platform is your computer?

Microsoft Windows NT 10.0.26200.0 x64

What terminal emulator and version are you using (if applicable)?

Ubuntu 24.04.3 LTS

What issue are you seeing?

■ unexpected status 403 Forbidden: Unknown error, url: https://chatgpt.com/backend-api/codex/responses, cf-ray: 9ef508e 138f4f5f3-AMS ⚠ MCP client for codex_apps failed to start: MCP startup failed: handshaking with MCP server failed: Send message error Transport [rmcp::transport::worker::WorkerTransport<rmcp::transport::streamable_http_client::StreamableHttpClientWorker<codex_rm cp_client::rmcp_client::StreamableHttpResponseClient>>] error: Unexpected content type: Some("missing-content-type; body: "), when send initialize request ⚠ MCP startup incomplete (failed: codex_apps)

What steps can reproduce the bug?

Uploaded thread: 019da606-bbbb-77d0-bda4-29b4ee9713dc

What is the expected behavior?

_No response_

Additional information

_No response_