Windows desktop app (MSIX 26.422.2437.0) stuck on blank splash - renderer infinite remount loop on workspace_dependencies feature flag

What version of the Codex App are you using?

• Codex desktop MSIX: 26.422.2437.0 (x64, installed from Microsoft Store)
• Bundled backend resources\codex.exe FileVersion: 0.124.0-alpha.2
• PackageFullName: OpenAI.Codex_26.422.2437.0_x64__2p2nqsd0c76g0

What subscription do you have?

ChatGPT Pro

What platform is your computer?

Windows 11 Pro, build 26200, x64

What issue are you seeing?

After launching Codex on Windows, the main window shows only a blank/white splash with the Codex >_ icon. It never progresses to the UI. Closing the window does not kill background processes — six Codex.exe processes remain (one ~850 MB, the rest smaller), and relaunching produces the same blank window.

Root cause visible in the desktop logs: the renderer (Electron) is in an infinite remount loop. Every ~100 ms it:

1. Logs app routes mounted after Xms (X grows unboundedly up to ~100 s)
2. Sends JSON-RPC experimentalFeature/enablement/set with feature workspace_dependencies
3. Gets back JSON-RPC error -32600: unsupported feature enablement 'workspace_dependencies': currently supported features are apps, memories, plugins, tool_search, tool_suggest, tool_call_mcp_elicitation
4. Throws, unmounts, remounts, repeats

In ~60 seconds of runtime the log accumulates 1922 workspace_dependencies errors and 961 route remounts.

So the shipped MSIX contains a frontend bundle that expects the experimental feature workspace_dependencies, but the backend shipped inside the same package (codex.exe 0.124.0-alpha.2) doesn't implement it and hard-rejects the enablement request. Frontend can't recover and spins.

A peer log line confirms the backend's feature list:
Features enabled enabledFeatures="enable_request_compression, collaboration_modes, personality, request_rule, fast_mode, image_generation, image_detail_original, workspace_dependencies, guardian_approval, apps, plugins, tool_search, tool_call_mcp_elicitation"

— workspace_dependencies is in the enabled set, but the experimentalFeature/enablement/set RPC explicitly rejects it as unsupported. That's the inconsistency.

What steps can reproduce the bug?

1. Install Codex from Microsoft Store (or let the app auto-update to 26.422.2437.0).
2. Launch it from Start menu.
3. Window opens, shows blank splash with >_ icon indefinitely.

What is the expected behavior?

App opens to the normal UI.

What did I try?

• Force-quit all Codex.exe processes via Stop-Process → relaunch. Same behavior.
• Full reset via Reset-AppxPackage (equivalent to Settings → Apps → Codex → Advanced options → Reset) → relaunch. Same behavior: 1922 workspace_dependencies errors, 961 remounts in a fresh profile. Confirms the bug is in shipped binaries, not in cached state.
• Checked Store for an updated MSIX — no newer version available yet.
• As a workaround, installed @openai/codex CLI 0.124.0 via npm. CLI works fine; desktop is the only broken path.

Representative log lines

First renderer feature-set request and the rejection that triggers the loop:
2026-04-24T12:02:07.120Z info [electron-message-handler] [startup][renderer] app routes mounted after 911ms
2026-04-24T12:02:07.nnnZ error [electron-message-handler] Request failed conversationId=none durationMs=XX
error={"code":-32600,"message":"unsupported feature enablement workspace_dependencies:
currently supported features are apps, memories, plugins, tool_search, tool_suggest, tool_call_mcp_elicitation"}
method=experimentalFeature/enablement/set
2026-04-24T12:02:07.nnnZ error [electron-message-handler] Failed to sync experimental feature enablement
error={"code":-32600,"message":"unsupported feature enablement workspace_dependencies ..."}
hostId=local