Quick answer
Pin the native Codex CLI to 0.104.0 temporarily, or run Codex inside WSL. Reports found 0.104 working where 0.105 and later builds crashed before startup. Retest newer releases later.
The exact error
Fatal Error: HW capability found: 0x178BFBFF 0x7EF8320B, but HW capability requested: 0x200000 0x00Do not use this guide for a merely similar message. The workaround is scoped to this signature and the environments below.
Match your environment
- Windows 11
- Codex CLI or VS Code extension
- Reported on AMD Ryzen systems
What to do
- 01
Confirm the signature
Use this guide only when the log includes both “HW capability found” and “HW capability requested.” A generic crash code can have a different cause.
- 02
Record the installed version
Run the version command before changing anything so you can compare failing and working states.
codex --version - 03
Temporarily pin the reported working version
If Codex was installed with npm, install the working release, restart the terminal, and verify it.
npm install -g @openai/codex@0.104.0 codex --versionNote: Do not keep an old tool pinned indefinitely. Retest the current release after checking the upstream issue.
- 04
Use WSL if you prefer not to downgrade
The same Windows users reported that running the Linux CLI inside WSL avoided the native executable crash.
What likely happened
The evidence points to a native Windows binary regression involving CPU capability detection on affected Ryzen machines. It does not establish that every capability-mismatch string has the same hardware cause.
First-hand sources
Source links support the environment and workaround claims above. An issue being closed does not by itself mean a fix shipped.