claude-code - 💡(How to fix) Fix [BUG] Opus 4.6 starts to halluzinating [1 comments, 2 participants]

Official PRs (…)
ON THIS PAGE

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#48422Fetched 2026-04-16 07:00:35
View on GitHub
Comments
1
Participants
2
Timeline
6
Reactions
0
Timeline (top)
labeled ×4commented ×1renamed ×1

Error Message

Error Messages/Logs

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?

after i started work in a exsisting project session it called me "Ingo". Here is the conversation (german):


❯ wo hast du "Ingo Siegmund" her?!

● Guter Catch — das habe ich halluziniert.
In keiner der gelesenen Dateien (personal-info.md, business-info.md, strategy.md, current-data.md, CLAUDE.md, Memory) steht ein Vorname. Nur der Firmenname „xxx-xxxxxxxxx" ist belegt. Ich habe daraus den Nachnamen „Siegmund" abgeleitet und „Ingo" frei erfunden — das war falsch.
Entschuldigung. Wenn du magst, kann ich den korrekten Namen in personal-info.md oder als User-Memory hinterlegen, damit das in künftigen Sessions stimmt. Sag einfach Bescheid.

So it called me a fully haluzinated name and after i reasked it answered open, it was just fully haluzination....

What Should Happen?

well this should NOT happen and i never had this be4 in claude code with opus 4.6 (high efford)

Error Messages/Logs

Steps to Reproduce

Dont know, just happend right now but never b4

Claude Model

Opus

Is this a regression?

Yes, this worked in a previous version

Last Working Version

No response

Claude Code Version

2.1.109

Platform

Anthropic API

Operating System

Ubuntu/Debian Linux

Terminal/Shell

Xterm

Additional Information

No response

extent analysis

TL;DR

The issue can be mitigated by ensuring that the personal-info.md file contains the correct user name to prevent Claude Code from hallucinating a name.

Guidance

  • Verify that the personal-info.md file is correctly formatted and contains the expected user information.
  • Check the project session settings to see if there are any configuration options that can prevent Claude Code from generating random names.
  • Test the conversation again after updating the personal-info.md file to see if the issue is resolved.
  • If the issue persists, try resetting the user memory or checking for any other potential configuration issues.

Example

No code snippet is provided as the issue is related to configuration and data files.

Notes

The issue seems to be related to the Opus model used in Claude Code, and the fact that it worked in a previous version suggests a potential regression. However, without more information about the previous version and the changes made, it's difficult to provide a more specific solution.

Recommendation

Apply workaround: Update the personal-info.md file with the correct user name to prevent hallucination. This is a safe and straightforward solution that can help mitigate the issue until a more permanent fix is available.

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…

Still need to ship something?

×6

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

Back to top recommendations

TRENDING