Error family guide
Codex Windows Sandbox Errors
Choose a page by the exact setup or runner message. Similar-looking Windows sandbox failures can require completely different actions.
Start with the full error string and numeric code. Confirm the client, Windows build, Codex version, and sandbox mode before changing permissions or reinstalling anything.
Safety boundary: this guide does not recommend disabling Windows Firewall, resetting broad ACLs, or switching to Full access as a generic fix.
Windows sandbox
Setup helper and policy initialization
Use these when the failure happens before a command reaches the runner.
Windows cannot find codex-windows-sandbox-setup.exe
Windows cannot find 'codex-windows-sandbox-setup.exe'Fix Codex when Windows cannot find codex-windows-sandbox-setup.exe or the sandbox helper reports program not found.
Open exact fix →Codex helper_unknown_error while applying deny-read ACLs
windows sandbox: helper_unknown_error: apply deny-read ACLsFix the confirmed corrupted-state branch of Codex windows sandbox: helper_unknown_error: apply deny-read ACLs, and identify when the workaround does not apply.
Open exact fix →Codex sandbox DPAPI error followed by setup error 0xc0000142
windows sandbox: CryptUnprotectData failed: 2148073483Diagnose Codex Windows sandbox recovery when CryptUnprotectData fails and moving .sandbox-secrets leads to codex-windows-sandbox-setup.exe error 0xc0000142.
Open exact fix →CoCreateInstance NetFwPolicy2 failed in Codex sandbox setup
helper_firewall_policy_access_failed: CoCreateInstance NetFwPolicy2 failed: HRESULT(0x80110474)Diagnose the Codex elevated Windows sandbox NetFwPolicy2 COM+ error without applying the unsafe junction used only for proof.
Open exact fix →Windows sandbox
Runner and process creation
Match the exact error number. Codes 5 and 1312 represent different Windows branches.
Codex Windows sandbox fails with CreateProcessAsUserW error 5
windows sandbox: runner error: CreateProcessAsUserW failed: 5Diagnose Codex Windows sandbox commands that fail before spawn with CreateProcessAsUserW failed: 5 (Access is denied).
Open exact fix →CreateProcessAsUserW failed: 1312 in the Codex Windows sandbox
windows sandbox: runner error: CreateProcessAsUserW failed: 1312Diagnose Codex Windows sandbox error 1312 when the runner loses or cannot create its logon session.
Open exact fix →Codex times out waiting for runner spawn_ready
windows sandbox: timed out after 15000ms waiting for runner spawn_readyDiagnose the open Codex Windows sandbox error timed out after 15000ms waiting for runner spawn_ready without confusing it with later pipe or token failures.
Open exact fix →Windows sandbox
Credentials, paths, and environment
Use these only when the error text names credentials, path normalization, or a WSL boundary.
Codex Windows sandbox fails HTTPS with SEC_E_NO_CREDENTIALS
SEC_E_NO_CREDENTIALS (0x8009030e)Diagnose Codex Windows sandbox HTTPS failures where PowerShell and Schannel curl return SEC_E_NO_CREDENTIALS but Python HTTPS works.
Open exact fix →AbsolutePathBuf deserialized without a base path on Windows
Error creating task Invalid request: AbsolutePathBuf deserialized without a base pathFix Codex Error starting chat: AbsolutePathBuf deserialized without a base path on Windows, VS Code, or WSL mode.
Open exact fix →Codex rewrites a WSL /mnt project path to a Windows drive
Project folder was deleted or movedFix Codex Linux Desktop in WSL2 when a valid /mnt project is displayed as D:\path and reported deleted or moved.
Open exact fix →Codex Linux sandbox helper ENOENT in WSL
Unable to spawn codex-linux-sandbox because it doesn't exist on the filesystem (ENOENT: No such file or directory)Fix Codex when codex-linux-sandbox does not exist and unified exec fails with ENOENT in Windows WSL mode.
Open exact fix →