Windows Desktop crash/hang with codex.exe MoBEX and node_repl/extension-host BEX64 after recent update

Summary

Codex Desktop on Windows started crashing/hanging repeatedly during normal use. The workflow had been stable for several days while using the bundled chrome, browser, computer-use, and node_repl capabilities. The instability began suddenly on July 6-7, 2026.

This does not look like a single conversation corrupting state. Windows Error Reporting shows repeated codex.exe MoBEX crashes first, followed by a cascade involving node_repl.exe, extension-host.exe, and the main Codex app.

Environment

• OS: Windows 11, x64, build family 10.0.26100
• Current installed package: OpenAI.Codex_26.623.19656.0_x64__2p2nqsd0c76g0
• Previously crashing package in WER: OpenAI.Codex_26.623.13972.0_x64__2p2nqsd0c76g0
• Local CLI reported earlier: codex-cli 0.130.0-alpha.5

Crash / Hang Timeline

Recent Windows Error Reporting entries:

• 2026-07-06 19:50-23:47: repeated MoBEX for OpenAI.Codex_26.623.13972.0_x64__2p2nqsd0c76g0, P5: codex.exe, P9: c0000409, P10: 0000000000000007
• 2026-07-07 00:09-00:44: repeated same codex.exe MoBEX / c0000409
• 2026-07-07 08:35 and 09:42: same codex.exe MoBEX / c0000409
• 2026-07-07 09:58:
• node_repl.exe crashed with BEX64, P10: 0000000000000007
• extension-host.exe crashed with BEX64, P10: 0000000000000007
• Codex main app reported MoAppCrash, module KERNELBASE.dll
• Codex app then reported MoAppHang
• 2026-07-07 11:19: Microsoft Store/AppX updated Codex from 26.623.13972.0 to 26.623.19656.0
• 2026-07-07 11:23: bundled plugin cache folders for browser, chrome, and computer-use were updated locally

What I Tried / Ruled Out

• Rotated a bloated/empty ~/.codex/logs_2.sqlite state file. This reduced disk pressure but did not explain the crash sequence.
• Observed high-frequency inserts into ~/.codex/logs_2.sqlite, then temporarily installed a SQLite trigger blocking inserts into logs and checkpointed/truncated WAL. After sampling, MAX(id), row count, and WAL size stopped growing, but Codex Desktop still crashed/hung.
• A very large conversation file was compacted from about 3.2 GB to a recent-turn subset and validated as well-formed JSONL. This reduced load pressure but did not eliminate the app instability.
• The same user workflow was stable before July 6-7 with chrome, browser, computer-use, and node_repl, so the likely boundary is the Windows desktop app/runtime/plugin-host layer rather than the mere use of those capabilities.

Available Local Artifacts

Crash dumps exist locally under:

• %LOCALAPPDATA%\CrashDumps\Codex.exe.3268324.dmp
• %LOCALAPPDATA%\CrashDumps\codex.exe.3094072.dmp
• %LOCALAPPDATA%\CrashDumps\codex.exe.3074908.dmp
• several more codex.exe.*.dmp files from 2026-07-07

I can provide redacted WER details or crash dumps if maintainers want a specific artifact.

Expected Behavior

Codex Desktop should not crash or hang when opening/continuing a thread or when the bundled node_repl / browser-related plugin hosts are active.

Actual Behavior

Codex Desktop repeatedly crashes or becomes unresponsive. Windows records MoBEX / c0000409 for codex.exe, followed by BEX64 crashes in node_repl.exe and extension-host.exe, then MoAppCrash / MoAppHang for the main app.

Related Issues

This seems related to the Windows crash/performance reports in:

• #28092
• #26812
• #16374
• #29177
• #27741
• #28224