Windows bundled marketplace EBUSY leaves Computer Use unavailable

What version of the Codex App are you using?

• Codex Desktop App: 26.609.4994.0
• Codex CLI: 0.140.0-alpha.2
• Bundled Browser / Computer Use plugin version: 26.609.41114
• CUA runtime: cua_node/789504f803e82e2b

What subscription do you have?

Not specified.

What platform is your computer?

• Windows x64
• PowerShell

What issue are you seeing?

Codex Desktop intermittently reports "Computer Use plugin is unavailable" in Settings, even though:

• computer_use is enabled.
• [plugins."computer-use@openai-bundled"] enabled = true is present in config.toml.
• The Computer Use native pipe starts successfully.
• The Computer Use runtime can successfully connect and list desktop applications.

The failure occurs because Codex attempts to delete and rebuild:

%USERPROFILE%\.codex\.tmp\bundled-marketplaces\openai-bundled

while processes are still loading files from that directory. On Windows, the locked files cannot be deleted. The marketplace reconciliation then fails and leaves a partially rebuilt directory containing only some bundled plugins. computer-use is omitted, so Settings reports that it is unavailable.

Observed locked files and processes included:

plugins\chrome\extension-host\windows\x64\extension-host.exe
plugins\browser\scripts\node_modules\classic-level\prebuilds\win32-x64\classic-level.node

The processes holding these files included extension-host.exe and a Codex CUA Node child process.

Relevant logs

[bundled-plugins] bundled_plugins_reconcile_started hasExternalPluginStateSync=true queued=false reason=startup

[computer-use-native-pipe] computer-use native pipe startup ready
pipePath=\\.\pipe\codex-computer-use-...
platform=win32

[BundledPluginsMarketplace] bundled_plugins_marketplace_resolve_failed
errorCode=EBUSY
errorMessage="EBUSY: resource busy or locked, rmdir
'C:\Users\<user>\.codex\.tmp\bundled-marketplaces\openai-bundled\plugins\chrome\extension-host\windows\x64'"

After the failed reconciliation, the temporary marketplace contained only:

plugins\browser
plugins\chrome

It did not contain:

plugins\computer-use
.agents\plugins\marketplace.json

The complete bundled marketplace, including computer-use, was still present inside the installed Codex App resources.

Steps to reproduce

The issue is intermittent, but the following sequence reproduces the underlying failure:

1. Use Browser, Chrome, or Computer Use so that Codex starts Node REPL / CUA Node / Chrome extension-host processes.
2. Leave one of these processes running with a module or executable loaded from the temporary bundled marketplace.
3. Restart or update Codex Desktop, causing bundled plugin marketplace reconciliation.
4. Codex attempts to remove and rebuild the temporary marketplace.
5. Windows rejects removal of the loaded executable or native .node module with EBUSY.
6. Marketplace reconciliation leaves a partial directory.
7. Open Settings > Computer Control.
8. Settings displays "Computer Use plugin is unavailable".

Expected behavior

Bundled plugin reconciliation should never leave a partial marketplace.

Before replacing the marketplace, Codex should:

1. Stop processes that load files from the existing temporary marketplace.
2. Build the new marketplace in a separate directory.
3. Validate that all expected manifests and plugin files exist.
4. Atomically switch to the new marketplace.
5. Keep the previous valid marketplace if cleanup or replacement fails.

If reconciliation fails, Computer Use should remain available from the last valid marketplace and Settings should surface a diagnostic error instead of reporting only that the plugin is unavailable.

Actual behavior

• Marketplace deletion fails because child processes still hold files open.
• Reconciliation leaves a partially populated marketplace.
• Computer Use disappears from the registered bundled plugins.
• Settings reports Computer Use as unavailable.
• The native pipe and runtime can still work, creating inconsistent UI and runtime states.
• Manually restoring files only works until a later reconciliation repeats the failure.

Workaround

The temporary workaround was:

1. Identify and stop the exact extension-host.exe / Codex Node process loading files from the temporary marketplace.
2. Delete the temporary bundled marketplace.
3. Restore a complete marketplace from the installed Codex App resources.
4. Explicitly enable computer_use.
5. Restart Codex Desktop.

This is not durable because future reconciliation can encounter the same file locks.

Related issues

• #19365: Windows Codex App: Browser Use unavailable because Node REPL tool is not exposed
• #19858: Codex Desktop leaks MCP server processes from internal title-generation sessions on Windows
• #18881: MCP child processes leak when McpConnectionManager is replaced
• #19753: Terminate stdio MCP servers on shutdown to avoid process leaks

This report appears distinct because the direct failure is an EBUSY error during bundled marketplace replacement, followed by a partially rebuilt marketplace and inconsistent Computer Use availability.