Issue Station
Sign In
Tools hereToolbox

claude-code - 💡(How to fix) Fix [BUG] Crash C000001D (ILLEGAL_INSTRUCTION) running claude.exe — request for AVX-free build [1 participants]

Official PRs (…)
ON THIS PAGE

Recommended Tools

×6

Utilities matched from this issue’s tags and category — try them while you read without losing context.

GitHub issue graph ai analysis

Paste a GitHub issue URL. We fetch that issue, discover linked issues from bodies/comments/timeline, collect linked pull requests, and produce a structured English report.

The report is written in English Markdown for sharing and archival.

Helpful · Quick feedback

Loading…
GitHub stats
anthropics/claude-code#54061•Fetched 2026-04-28 06:40:17
View on GitHub
Comments
0
Participants
1
Timeline
3
Reactions
0
Author
antonio-leonardoantonio-leonardo
Participants
antonio-leonardoantonio-leonardo
Timeline (top)
labeled ×3

Error Message

  • Behavior: The process exits immediately with an unhandled exception: C000001D (ILLEGAL_INSTRUCTION).

Error Messages/Logs

Root Cause

Interpretation: The crash appears to be caused by the binary executing CPU instructions not supported by this older CPU (ILLEGAL_INSTRUCTION). This suggests the build requires modern SIMD instruction sets (AVX/AVX2 or similar).

RAW_BUFFERClick to expand / collapse

Preflight Checklist

  • I have searched existing issues and this hasn't been reported yet
  • This is a single bug report (please file separate reports for different bugs)
  • I am using the latest version of Claude Code

What's Wrong?

Crash C000001D (ILLEGAL_INSTRUCTION) running claude.exe — request for AVX-free build

Hello Anthropic team,

I am reporting an immediate crash when launching the native binary included with the Claude Code extension. Below are the key technical details:

  • Behavior: The process exits immediately with an unhandled exception: C000001D (ILLEGAL_INSTRUCTION).
  • Environment: Windows; the executable is signed and the Authenticode signature verifies as valid. Static dependency checks with Dependencies show no missing DLLs.
  • Diagnostic artifact: I captured a ProcDump at the time of the crash: claude.exe_260427_171257.dmp (available for analysis).
  • Hardware: Intel Core2 Duo P7550 @ 2.26GHz. Coreinfo output indicates no AVX or AVX2 support; SSE4.2 is also absent.

Interpretation: The crash appears to be caused by the binary executing CPU instructions not supported by this older CPU (ILLEGAL_INSTRUCTION). This suggests the build requires modern SIMD instruction sets (AVX/AVX2 or similar).

Request

  1. Please provide an alternative build of the native client compiled without AVX/AVX2 (a fallback build compatible with older CPUs).
  2. Alternatively, confirm the minimum CPU instruction set requirements for the current release so I can plan appropriate hardware or VM usage.

I can provide the following artifacts for your analysis:

  • ProcDump file: claude.exe_260427_171257.dmp
  • Coreinfo output showing CPU feature flags
  • SHA256 hash of the executable and the Dependencies log

Please indicate the preferred secure channel or ticketing method for uploading these artifacts.

Thank you for your help — I can supply any additional logs or steps you request.

Best regards,
Antônio

What Should Happen?

Crash C000001D (ILLEGAL_INSTRUCTION) running claude.exe — request for AVX-free build

Error Messages/Logs

Steps to Reproduce

<!-- Failed to upload "claude.exe_260427_171257.dmp" --> <!-- Failed to upload "claude.exe_260427_171257.zip" -->

Claude Model

None

Is this a regression?

Yes, this worked in a previous version

Last Working Version

No response

Claude Code Version

2.1.120.0

Platform

Other

Operating System

Windows

Terminal/Shell

VS Code integrated terminal

Additional Information

The dump file is too big

extent analysis

TL;DR

The most likely fix is to provide an alternative build of the native client compiled without AVX/AVX2 to support older CPUs.

Guidance

  • The crash is likely caused by the binary executing CPU instructions not supported by the older CPU, specifically AVX or AVX2 instructions.
  • To verify, analyze the ProcDump file claude.exe_260427_171257.dmp to confirm the crash is due to an illegal instruction.
  • Consider providing a fallback build of the native client that is compatible with older CPUs, such as those without AVX or AVX2 support.
  • Alternatively, confirm the minimum CPU instruction set requirements for the current release to help plan appropriate hardware or VM usage.

Example

No code snippet is provided as it is not necessary for this issue.

Notes

The issue is likely specific to older CPUs without AVX or AVX2 support, and providing a compatible build or confirming the minimum CPU requirements can help resolve the issue.

Recommendation

Apply workaround: Provide an alternative build of the native client compiled without AVX/AVX2 to support older CPUs, as this is the most straightforward solution to address the compatibility issue.

Vote matrix · Quick signals

Works
Did the solution work? Tap to confirm.
Easy Fix
Was it a quick fix?
Time Saver
Did it save you time?
Blocking
Was it severely blocking?
Common Issue
Are others likely hitting this too?
Flaky / Intermittent
Is it intermittent?
Verified / Reproducible
Can you reproduce it reliably?
Loading…
#api#ssr#installation#tensor shape#autograd error

Still need to ship something?

×6

Another batch ranked right after the header list — different links, same matching logic.

Back to top recommendations

TRENDING

claude-code - 💡(How to fix) Fix [BUG] Crash C000001D (ILLEGAL_INSTRUCTION) running claude.exe — request for AVX-free build [1 participants]