[Windows desktop] Chrome native host retry loop consumes a CPU core and causes input lag #38510

Codex App version

• Windows MSIX package: OpenAI.Codex 26.810.4967.0
• Previous package before the update: 26.803.10989.0

Platform

• Windows 11 Enterprise 25H2, build 26200.9168, x64

Issue

After updating the Codex desktop app, the Windows desktop developed severe keyboard and mouse input stutter while Codex was running. Closing Codex removed the stutter, and rebooting or relaunching temporarily restored normal responsiveness before the symptom returned.

The Codex main process sustained approximately 100-140% of one logical CPU core during affected periods. System-wide CPU utilization, DPC activity, interrupt activity, memory pressure, and device status were otherwise normal.

The desktop log repeatedly emitted this warning every approximately 0.3-0.5 seconds:

[chrome-native-host-cache-watcher] chrome_native_host_cache_reconcile_failed
errorMessage="Missing bundled Electron runtime required to sync Chrome native host resources for com.openai.codexextension: codex
(resourcesPath: <WindowsApps package>\app\resources)."
marketplaceName=openai-bundled
pluginName=chrome

One session accumulated 1,288 copies of the same warning and grew to about 5.1 MB. No raw logs are attached because they contain local paths and conversation metadata.

The retry loop eventually stopped spontaneously before the Chrome plugin was manually disabled. After setting:

[plugins."chrome@openai-bundled"]
enabled = false

no additional copies of this warning were observed during a 10-second verification window. A full restart after disabling is still needed to confirm the workaround across a fresh process.

Steps to reproduce

1. Install or update to Windows MSIX package 26.810.4967.0.
2. Leave the bundled chrome@openai-bundled plugin enabled.
3. Launch Codex and use it normally.
4. Wait until chrome_native_host_cache_reconcile_failed begins repeating in the desktop log.
5. Observe sustained main-process CPU usage and keyboard/mouse input stutter outside Codex.
6. Close Codex; system responsiveness returns.

The onset is not fully deterministic, but the log loop and CPU increase are directly measurable when the problem is active.

Expected behavior

• The Windows package should include or correctly locate the runtime required by the bundled Chrome plugin.
• A missing runtime should produce one actionable diagnostic and use bounded exponential backoff, rather than retrying several times per second.
• A plugin initialization failure should not consume a CPU core or degrade system-wide input responsiveness.
• If the bundled runtime is unavailable, the plugin should fail closed or disable itself with a clear notification.

Privacy note

This report is intentionally sanitized. Usernames, account details, user-directory paths, conversation/task IDs, process IDs, IP addresses, device identifiers, and raw logs have been omitted.