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Codex Issues / #25671

Windows app fails on fresh install - Electron app not found / app-server unavailable

Open 💬 4 comments Opened Jun 1, 2026 by TheBeefBai
💡 Likely answer: A maintainer (github-actions[bot], contributor) responded on this thread — see the highlighted reply below.

What version of the Codex App are you using (From “About Codex” dialog)?

26.527.7698.0

What subscription do you have?

Workplace Group

What platform is your computer?

Microsoft Windows NT 10.0.26200.0 x64

What issue are you seeing?

After a fresh installation, Codex fails to start correctly.

Observed errors:

"Unable to find Electron app at ...\app\codex...\new"
"Failed to resume chat: failed to resolve rollout path"
"Codex app-server is not available"

Troubleshooting performed:

Uninstalled and reinstalled Codex multiple times
Rebooted Windows
Deleted C:\Users\joshr.codex
Reset the AppX package
Verified package status is OK:
Status: Ok
IsPartiallyStaged: False
Confirmed package contents exist under:
C:\Program Files\WindowsApps\OpenAI.Codex_26.527.7698.0_x64__2p2nqsd0c76g0\app

Findings:

Direct launch of:
app\Codex.exe
opens the UI.
Starting a chat then produces:
"Codex app-server is not available"
The package contains app\Codex.exe but does not contain an app\codex directory.
The Electron error appears to reference a path that does not exist in the installed package.

PowerShell output:
Test-Path "$((Get-AppxPackage OpenAI.Codex).InstallLocation)\app"
True

Test-Path "$((Get-AppxPackage OpenAI.Codex).InstallLocation)\app\codex"
False

What steps can reproduce the bug?

Scenario 1: Fresh Installation Fails with Electron Error

  1. On Windows 11, install the Codex desktop app using the installer downloaded from openai.com.
  2. Allow the installer to install the application through the Microsoft Store.
  3. Complete installation.
  4. Launch Codex from the Start Menu.

Expected Result

Codex launches normally and displays the chat interface.

Actual Result

Codex immediately displays an error:

"Unable to find Electron app at ...\app\codex...\new"

The application cannot be used.

Additional Findings

The installed package contains:

...\app\Codex.exe

but does not contain:

...\app\codex

PowerShell results:

Test-Path "$((Get-AppxPackage OpenAI.Codex).InstallLocation)\app"
True

Test-Path "$((Get-AppxPackage OpenAI.Codex).InstallLocation)\app\codex"
False

---

Scenario 2: Direct Launch Opens UI but Chat Cannot Start

  1. Launch Codex directly using:

& "$((Get-AppxPackage OpenAI.Codex).InstallLocation)\app\Codex.exe"

  1. Sign in successfully.
  2. Attempt to start a new chat or send the first message.

Expected Result

A new chat is created and the message is sent.

Actual Result

One of the following errors occurs:

  • "Failed to resume chat: failed to resolve rollout path"
  • "Codex app-server is not available"

The application UI loads but cannot create or use conversations.

---

Troubleshooting Performed

  • Multiple uninstall/reinstall cycles
  • Windows reboot
  • Deleted C:\Users\joshr.codex
  • Reset AppX package
  • Verified package status is OK
  • Verified no OneDrive redirection
  • Verified local profile path is standard
  • Windows Defender only (no third-party antivirus)

The issue reproduces on a completely fresh installation before any successful chat session has ever been created.

What is the expected behavior?

_No response_

Additional information

_No response_

View original on GitHub ↗

4 Comments

github-actions[bot] contributor · 2 months ago

Potential duplicates detected. Please review them and close your issue if it is a duplicate.

  • #25489
  • #25297
  • #25598
  • #25635
  • #25188

Powered by Codex Action

whl0901 · 2 months ago

I can reproduce this on:

OpenAI.Codex_26.527.7698.0_x64__2p2nqsd0c76g0
Windows
Package status: Ok
IsPartiallyStaged: False

I ran additional diagnostics and found that the app-server launch path appears to be wrong.

Installed package paths:

app\Codex.exe exists
app\resources\codex.exe exists
app\resources\codex exists
app\resources\app.asar exists

Missing paths:

app\app-server does not exist
app\codex does not exist
app\codex\app-server does not exist

AppxBlockMap also does not contain:

app\app-server
app\codex
app\codex\app-server

The bundled app-server binary seems valid:

Directly running app\resources\codex.exe from WindowsApps gives Access is denied, but after copying the same binary to %TEMP%, it runs successfully:

codex.exe --version
=> codex-cli 0.136.0-alpha.2

codex.exe app-server --help
=> works and prints app-server help.

The npm global CLI is also working:

@openai/codex@0.135.0
codex --version
=> codex-cli 0.135.0

codex app-server --help
=> works.

Most important finding from process tracing:

When launching Codex Desktop, the main process is:

C:\Program Files\WindowsApps\OpenAI.Codex_26.527.7698.0_x64__2p2nqsd0c76g0\app\Codex.exe

But the desktop app repeatedly spawns:

ExecutablePath:
C:\Program Files\WindowsApps\OpenAI.Codex_26.527.7698.0_x64__2p2nqsd0c76g0\app\codex.exe

CommandLine:
codex.exe app-server --analytics-default-enabled

On Windows, app\codex.exe resolves case-insensitively to app\Codex.exe, which is the Electron shell, not the bundled CLI/app-server binary at app\resources\codex.exe.

This explains the observed error:

Unable to find Electron app at:
...\app\app-server

Cannot find module:
...\app\app-server

Manual repro:

& "$((Get-AppxPackage OpenAI.Codex).InstallLocation)\app\Codex.exe" app-server

This reproduces the same Electron error.

Hypothesis:

The Windows desktop app-server launcher should probably invoke:

app\resources\codex.exe app-server --analytics-default-enabled

but it currently invokes or resolves to:

app\codex.exe app-server --analytics-default-enabled

which maps to the Electron shell app\Codex.exe on Windows.

whl0901 · 2 months ago

Confirmed workaround / root cause evidence:

After patching a loose-folder copy of the app, Codex UI opens successfully.

Patch used:

  1. Copy the MSIX app folder out of WindowsApps to a normal directory.
  2. Rename the Electron shell:

Codex.exe -> CodexShell.exe

  1. Copy the real bundled CLI/app-server binary:

resources\codex.exe -> codex.exe

  1. Launch:

CodexShell.exe

Result:
The Codex UI opens successfully.

This confirms that the app-server launch failure is caused by the desktop app spawning a bare:

codex.exe app-server --analytics-default-enabled

which resolves to the Electron shell Codex.exe on Windows, instead of the real bundled app-server binary:

resources\codex.exe

Before the patch, the desktop log showed:

[StdioConnection] stdio_transport_spawned argsCount=2 executablePath=codex.exe spawnCommand=codex.exe

Then the child process output was:

正於現有瀏覽器工作階段中開啟。

The app then tried to parse that as MCP JSON and failed:

Failed to parse MCP message
Unexpected token '正' ... is not valid JSON

After replacing same-folder codex.exe with the real resources\codex.exe, the UI opens.

whl0901 · 2 months ago

Update after installing the latest 6/6 Windows Store update:

The same app-server launcher issue still appears to reproduce.

Previously, on 26.601, I confirmed a workaround by patching a loose-folder copy:

  1. Copy the app folder out of WindowsApps.
  2. Rename:

Codex.exe -> CodexShell.exe

  1. Copy:

resources\codex.exe -> codex.exe

  1. Launch:

CodexShell.exe

Result:
The Codex UI opened successfully.

After updating again to the latest Store version, launching the official packaged app again fails with the same app-server issue.

Prior logs showed:

[StdioConnection] stdio_transport_spawned argsCount=2 executablePath=codex.exe spawnCommand=codex.exe

Then the child process output was:

正於現有瀏覽器工作階段中開啟。

Codex then tried to parse that as MCP JSON and failed:

Failed to parse MCP message
Unexpected token '正' ... is not valid JSON

Then:

Codex app-server process closed unexpectedly

This still suggests the Windows desktop launcher is spawning a bare:

codex.exe app-server --analytics-default-enabled

which resolves to the Electron shell Codex.exe on Windows, instead of the real bundled app-server binary:

resources\codex.exe