Invalid request: missing field `inputSchema`
Community-confirmed cause: a stale `CODEX_CLI_PATH` override or cached old `codex.exe` makes the desktop app launch an outdated app-server that rejects the new build's dynamic tools. Delete the registry value (`reg delete HKCU\Environment /v CODEX_CLI_PATH /f`), remove any `CODEX_CLI_PATH` line from `~/.codex/config.toml`, clear stale binaries under `%LOCALAPPDATA%\OpenAI\Codex`, and relaunch. Until then, create the thread from the CLI and resume it in the app.
Affected versions: Desktop 26.616.x through 26.707 on Windows; triggered by stale CLI binaries in the 0.130–0.140 range
Since a mid-June 2026 auto-update, the Codex desktop app on Windows throws this toast the moment you start a new conversation or project, while every already-open thread keeps working (#28978). The CLI, pointed at the exact same ~/.codex/config.toml, starts new threads without complaint — the tell that the app is launching an older Codex binary than the one it shipped with.
Symptoms
- Every new conversation or project in the desktop app fails instantly with the toast; restarting the app changes nothing (#28978).
- Existing conversations resume and chat normally — only the new-thread path is broken (#28978, #29250).
codex execwith the identical config completes turns cleanly (#28978).- Scheduled automations can get auto-archived the same day, because scheduled runs hit the same thread-creation failure (#28978).
Cause
There is no maintainer response in the thread as of July 15, 2026, but the community diagnosis is consistent across more than a dozen independent Windows and WSL2 reports (#28978). The desktop app injects its own codex_app-namespace dynamic tools when starting a thread, and newer builds deserialize tool definitions more strictly. If a stale override makes the app launch an old app-server — one reporter’s CODEX_CLI_PATH was pinned to 0.135 while the updated app expected 0.142 — that old server rejects the new app’s tool payload with this exact error (#28978). The override hides in several places that survive app updates: an HKCU\Environment registry value, a CODEX_CLI_PATH line in ~/.codex/config.toml, stale extracted binaries under %LOCALAPPDATA%\OpenAI\Codex\bin that a Store update never refreshed, and old codex-desktop-* folders under %USERPROFILE%\.codex\bin (#28978).
Fix
- Delete the registry override:
reg delete HKCU\Environment /v CODEX_CLI_PATH /f, then restart — one reporter needed a full reboot before it took (#28978). - Remove any
CODEX_CLI_PATH = ...line from~/.codex/config.toml. One user found the app wrote the stale path back on next launch after detecting a legacy install folder, so remove or rename that old folder too (#28978). - Clear the cached runtimes: delete the
binandruntimesfolders under%LOCALAPPDATA%\OpenAI\Codexso the app re-extracts current binaries (#28978). - Relaunch the desktop app and start a new conversation.
- Need a working thread before the cleanup? Create it from the CLI (
codexin the project directory), then open it in the app — the resume path does not trigger the failure (#28978).
Affected versions
Reports start on Desktop 26.616 (opened June 18, 2026) and continue through Desktop 26.707 as of July 11 (#28978). The stale binaries implicated fall in the CLI 0.130–0.140 range; users report 0.142.0 and later working once the app actually launches it (#28978).
Facts on this page verified July 15, 2026.