Troubleshooting hub
Codex error fixes
Fix Codex Windows sandbox, WSL, configuration, CPU capability, Desktop, CLI, and VS Code errors.
Start with the exact error, then confirm the operating system, client, and version. Do not apply a workaround solely because the product name matches.
Choose by error family: Windows sandbox, startup/bootstrap, or thread and queue errors.
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 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 fix →App-server queued follow-up no longer exists
App-server queued follow-up no longer existsRecover from the Codex Desktop app-server queued follow-up error after editing, cancelling, or resending a queued message.
Open fix →Windows setup didn't finish: helper_failed
Windows setup didn't finishRoute the Codex Windows setup loop to its real helper, ACL, state-file, or UAC branch before changing system permissions.
Open 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 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 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 fix →Codex bundled MCP fails with JSON-RPC error -32603
MCP startup failed: handshaking with MCP server failed: JSON-RPC error: -32603Diagnose Messages and Computer History MCP startup failures caused by an experimental capability compatibility mismatch.
Open fix →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 fix →account/read failed during TUI bootstrap
Error: account/read failed during TUI bootstrapDiagnose Codex CLI account/read startup failures by the nested error instead of treating every case as a login problem.
Open 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 fix →Codex Browser fails because browser-client is not trusted
privileged native pipe bridge is not available; browser-client is not trustedDiagnose Codex Browser plugin failures caused by a missing native pipe trust bridge or a browser-client path outside configured trusted code paths.
Open fix →bwrap loopback Failed RTM_NEWADDR: Operation not permitted
bwrap: loopback: Failed RTM_NEWADDR: Operation not permittedFix the Codex Linux sandbox bwrap loopback RTM_NEWADDR error with the current Ubuntu AppArmor profile guidance.
Open fix →bwrap cannot create the Codex synthetic mount directory in /tmp
bwrap: Can't mkdir /tmp/codex-bwrap-synthetic-mount-targets-1000: Read-only file systemDiagnose Codex startup when a managed Linux permission profile denies /tmp before the sandbox helper can create its mount directory.
Open fix →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 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 fix →idle timeout waiting for SSE hides response.failed
idle timeout waiting for SSEDiagnose Codex CLI 0.153.4 when an SSE terminal failure is replaced by a later idle-timeout message.
Open 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 fix →Codex Remote Control WebSocket returns HTTP 503
failed to connect to app-server remote control websocketSeparate a Codex Remote Control upstream WebSocket 503 from enrollment, local task, proxy, and network problems.
Open fix →Codex Desktop SQLite pool times out during startup
Codex cannot access its local databaseRecover Codex Desktop when logs_2.sqlite grows large and startup fails with pool timed out while waiting for an open connection.
Open fix →configRequirements/read fails with No file descriptors available
configRequirements/read failed during TUI bootstrapDiagnose Codex TUI bootstrap when app-server file-descriptor exhaustion is mislabeled as a requirements-file error.
Open fix →thread history projection expected ordinal N, got N-1
thread-store internal error: thread history projection ... expected ordinal 192591, got 192590 (code -32603)Recover safely when a long Codex thread cannot fork or resume because its thread-history projection ordinal is out of sync.
Open fix →Codex app-server initialize handshake times out in WSL mode
Codex app-server initialize handshake timed outDiagnose Codex Desktop WSL startup when the app-server initialize handshake times out and nested logs show bwrap relocation ENOENT.
Open fix →Codex fatal error: HW capability requested
Fatal Error: HW capability found: 0x178BFBFF 0x7EF8320B, but HW capability requested: 0x200000 0x00.Work around Codex native Windows fatal error when detected CPU hardware capability does not match the requested capability.
Open fix →Codex config.toml missing escaped value on Windows
failed to reload config: missing escaped value, expected `b`, `e`, `f`, `n`, `r`, `\`, `"`, `x`, `u`, `U`Fix Codex config.toml missing escaped value on Windows by using valid TOML paths with forward slashes or literal strings.
Open 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.
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