Codex app-server repeatedly exits on Windows; crash dialog surfaces plugin metadata and PowerShell shell_snapshot WARNs

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

Version 26.601.21317 • Released Jun 2, 2026

What subscription do you have?

Enterprise

What platform is your computer?

Microsoft Windows NT 10.0.26200.0 x64

What issue are you seeing?

Codex app-server crashes on Windows while loading a cached plugin manifest. This happens in both Codex Desktop and Codex in VS Code, including when the chat is idle.

The error points to a cached ngs-analysis plugin manifest where interface.defaultPrompt[0] is longer than Codex's 128-character limit.

Error message:

Codex process errored: Codex app-server process exited unexpectedly (code=1 (0x1), signal=null).

Last CLI error:
2026-06-04T17:58:16.573645Z WARN codex_core_plugins::manifest: ignoring interface.defaultPrompt[0]: prompt must be at most 128 characters path=C:\Users\<user>\.codex\.tmp\plugins\plugins\ngs-analysis\.codex-plugin/plugin.json
2026-06-04T17:58:16.573800Z WARN codex_core_plugins::manifest: ignoring interface.defaultPrompt[0]: prompt must be at most 128 characters path=C:\Users\<user>\.codex\.tmp\plugins\plugins\ngs-analysis\.codex-plugin/plugin.json

The offending cached manifest contains a defaultPrompt string around 313 characters long, while Codex logs that it must be at most 128 characters.

The plugin is not explicitly enabled in my config.toml.

What steps can reproduce the bug?

1. Use Codex Desktop or Codex in VS Code on Windows.
2. Let Codex load/sync the plugin cache under: C:\Users\<user>\.codex\.tmp\plugins
3. The regenerated cache includes: C:\Users\<user>\.codex\.tmp\plugins\plugins\ngs-analysis\.codex-plugin\plugin.json
4. Start Codex Desktop or Codex in VS Code.
5. Codex logs:

WARN codex_core_plugins::manifest: ignoring interface.defaultPrompt[0]: prompt must be at most 128 characters

1. The Codex app-server exits unexpectedly with code 1.

This can happen even if the chat is idle.

I tried closing Codex and renaming these cache folders:

$codex = "$env:USERPROFILE\.codex"
$stamp = Get-Date -Format "yyyyMMdd-HHmmss"

Copy-Item "$codex\config.toml" "$codex\config.toml.bak-$stamp"

if (Test-Path "$codex\.tmp\plugins") {
Rename-Item -LiteralPath "$codex\.tmp\plugins" -NewName "plugins.bak-$stamp"
}

if (Test-Path "$codex\.tmp\bundled-marketplaces") {
Rename-Item -LiteralPath "$codex\.tmp\bundled-marketplaces" -NewName "bundled-marketplaces.bak-$stamp"
}
This only helps temporarily. Codex regenerates the plugin cache and the same bad ngs-analysis manifest returns.

Session id, if useful:

019e93bd-8c64-7393-898a-caeb32608d4c
Token limit usage / context window usage: not available.

What is the expected behavior?

Codex should not crash because of an invalid cached plugin manifest.

At minimum, Codex should skip or ignore the invalid plugin and continue running, especially if the plugin is not explicitly enabled in config.toml.

Additional information

The regenerated plugin cache appears to be a git repo:

origin: https://github.com/openai/plugins.git
branch: main
HEAD: 265aae0869eaffa7e00e368fb86c87d930dc69af

The problematic cached manifest path is:

C:\Users\<user>\.codex\.tmp\plugins\plugins\ngs-analysis\.codex-plugin\plugin.json

The manifest contains a long defaultPrompt similar to:

"defaultPrompt": [
"Guide me through the minimum required NGS analysis questions, inspect available BCL/FASTQ files or count matrices, choose the right public pipeline or deeper assay-specific skill, check whether required tools already exist, and execute supported local workflows with pre-execution validation and artifact capture."
]

This does not appear to be caused by Windows path length. The error is about the character length of the prompt string inside the plugin manifest.

A temporary local workaround is to shorten interface.defaultPrompt[0] to fewer than 128 characters. However, this may be overwritten when Codex resyncs the plugin cache.

After locally shortening interface.defaultPrompt[0], Windows PowerShell Set-Content -Encoding UTF8 wrote the file with a UTF-8 BOM. Codex then failed to parse the manifest with:

failed to parse plugin manifest: expected value at line 1 column 1
Rewriting the file as UTF-8 without BOM fixed that local parse error. The original issue remains: the regenerated upstream cached ngs-analysis manifest contains a defaultPrompt longer than Codex's 128-character limit.

Disabling [plugins."teams@openai-curated"] did not prevent Codex from regenerating/loading C:\Users\<user>\.codex\.tmp\plugins, and the invalid ngs-analysis manifest returned.

After patching the cached plugin metadata issues, Codex crashed again with a different last CLI warning:

Failed to create shell snapshot for powershell: Shell snapshot not supported yet for PowerShell
target="codex_core::shell_snapshot"

This may be related to #19382 and #16886, but this report is specifically about the Codex app-server exiting with code 1 on Windows/Desktop/VS Code due to the regenerated ngs-analysis cached plugin manifest.

Codex crashed with the following error:

  (code=null, signal=SIGSEGV).
Most recent error: {"timestamp":"2026-06-05T14:04:49.795646Z","level":"WARN","fields":{"message":"ignoring interface.defaultPrompt[0]: prompt must be at most 128 characters","path":"/Users/<user>/.codex/.tmp/plugins/plugins/ngs-analysis/.codex-plugin/plugin.json"},"target":"codex_core_plugins::manifest"}