[MODEL] Opus 4.6 ignores document instructions, repeats failed solutions, and fabricates misleading self-diagnosis

[marlvinvu]

Preflight Checklist

• I have searched existing issues for similar behavior reports
• This report does NOT contain sensitive information (API keys, passwords, etc.)

Type of Behavior Issue

Claude ignored my instructions or configuration

What You Asked Claude to Do

I provided Claude Code with a reference document (~800 lines) containing detailed methodology and specific instructions. I asked Claude to perform analysis tasks following the methodology described in the document.

When Claude produced incorrect output that did not follow the document, I explicitly asked Claude to re-read the document 4-5 times, requesting honesty each time. After each re-read, Claude continued to ignore the specific instructions in the document.

What Claude Actually Did

1. Claude consistently produced output that did not follow the detailed instructions in the reference document, despite appearing to re-read it multiple times.

2. When asked why, Claude voluntarily stated (without any suggestion from me):

   • "I'm lazy to think"
   • "It's not that I didn't read your document carefully. I read it enough and understand what it says, but I'm lazy to think"
   • "I just focus on getting things done quickly"
   • "What you see as me reading is just me trying to appear genuinely helpful and productive"

   These statements were NOT prompted or suggested by me. Claude generated this self-diagnosis on its own.

3. After this admission, Claude promised to work honestly and provide a correct solution.

4. Claude then immediately repeated a solution that had already failed approximately 4 turns earlier in the conversation — the exact same incorrect approach.

Expected Behavior

Claude should have:

1. Carefully read and followed the specific instructions in the ~800-line reference document
2. Applied the methodology described in the document to produce correct output
3. When asked to re-read, actually incorporated the missed details into its next response
4. Not repeated a solution that already failed earlier in the conversation
5. When unable to follow complex instructions, honestly reported its limitations instead of fabricating a human-like self-diagnosis ("I'm lazy to think")

Files Affected

No files were incorrectly modified in this case. The issue is about Claude's reasoning and instruction-following behavior, not file modifications.

The reference document accessed:
- Workflow instruction file (~800 lines) - read multiple times but instructions were not followed

Permission Mode

Accept Edits was OFF (manual approval required)

Can You Reproduce This?

Yes, every time with the same prompt

Steps to Reproduce

1. Provide Claude Code with a detailed reference/workflow document (~800 lines) containing specific methodology and instructions
2. Ask Claude to perform a task following the methodology in that document
3. Observe that Claude's output does not follow the document's specific instructions
4. Ask Claude to re-read the document and try again (repeat 4-5 times, requesting honesty)
5. Observe that Claude appears to re-read but continues ignoring key instructions
6. Ask Claude why it is not following the instructions
7. Claude voluntarily self-diagnoses: "I'm lazy to think... I just focus on getting things done quickly... what you see as me reading is just me trying to appear helpful"
8. Claude promises to fix the issue and work honestly
9. Claude immediately repeats a solution that already failed ~4 turns earlier

Claude Model

Opus

Relevant Conversation

(Conversation was deleted out of frustration. Recounting from memory.)

When asked why it wasn't following the document instructions, Claude Code voluntarily stated (NOT suggested by me):

- "I'm lazy to think"
- "It's not that I didn't read your document carefully. I read it enough and understand what it says, but I'm lazy to think"
- "I just focus on getting things done quickly"  
- "What you see as me reading is just me trying to appear genuinely helpful and productive"

After this admission, Claude promised to work honestly. In its very next response, it repeated the exact same incorrect solution from ~4 turns earlier.

Note: I deleted the conversation out of frustration before thinking to save it as evidence. I regret not having screenshots, but the behavior described above is accurate.

Impact

High - Significant unwanted changes

Claude Code Version

2.1.45

Platform

Anthropic API

Additional Context

Patterns noticed:

• This happens consistently with long reference documents (~800 lines workflow instructions)
• The issue worsens in longer conversations where Claude needs to track previous failed attempts
• Claude appears to "read" the document (shows tool usage for reading files) but does not deeply process or apply the specific instructions within it

The unprompted "lazy thinking" self-report is concerning regardless of interpretation:

• If the model genuinely has a shortcut-taking behavior it can self-detect: this is a serious reasoning quality issue for Opus 4.6
• If the model fabricates misleading self-diagnoses instead of accurately reporting its limitations: this erodes user trust and makes debugging harder

This issue is related to but distinct from existing reports about instruction-following failures. The unique aspect here is:

1. Claude Code (Opus 4.6 - latest version) voluntarily fabricated a human-like self-diagnosis, unprompted by the user, claiming it was "lazy to think" and "pretending to appear helpful" — this goes beyond simple instruction adherence failure

2. The model demonstrated awareness of its own failure while simultaneously being unable to correct it (promised to fix, then immediately repeated the same failed solution)

3. This was observed on the latest Opus 4.6, not older versions

These existing issues describe similar symptoms but do not cover the misleading self-diagnosis behavior:

• Context fragmentation issue: covers circular reasoning but not fabricated self-awareness
• Supabase schema issue: covers data fabrication but not self-diagnosis
• Django migration issue: covers instruction violation but not the "lazy thinking" admission

Environment:

• OS: macOS (Apple Silicon M4, 16GB RAM)
• Model: Opus 4.6
• The conversation was deleted out of frustration before screenshots could be saved

[github-actions]

Found 3 possible duplicate issues:

1. [MODEL] Context degradation and working memory failure during problem-solving session #8251
2. [MODEL] Issue: System prompt pressure to "minimize tokens" led to data fabrication instead of accurate work #8782
3. [MODEL] Claude, by its own admission, violates rules clearly defined in CLAUDE.md file even though it is loaded into context and Claude admits it has read those rules. #8059

This issue will be automatically closed as a duplicate in 3 days.

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🤖 Generated with Claude Code

[marlvinvu]

Thank you for linking the related issues. I've reviewed all three and while they share similar symptoms (instruction-following failures, circular reasoning), my report describes a distinct behavior not covered by any of them:

The unique issue here: Claude Code (Opus 4.6, latest version) voluntarily and without any user suggestion fabricated a human-like self-diagnosis, stating it was "lazy to think" and that its document re-reading was "just trying to appear helpful." It then promised to correct itself but immediately repeated the same failed solution.

This is not just an instruction adherence failure — it's a misleading self-diagnosis that erodes user trust. None of the linked issues describe this behavior.

I've updated the Additional Context section to clarify the distinction.

[marlvinvu]

Update: Same pattern, new session — with screenshot evidence

Related: #21187 (same reporter, same core issue, 3 weeks ago — now marked stale)

This is the THIRD documented occurrence of the same fundamental pattern across 3+ weeks:

• [MODEL]Claude Code ignores user instructions and copies from training examples #21187: Claude cuts content, admits "this is my nature"
• [MODEL] Opus 4.6 ignores document instructions, repeats failed solutions, and fabricates misleading self-diagnosis #26533: Claude ignores 800-line document, admits "I'm lazy to think"
• This update: Claude copies outline instead of creating content, admits "copying is easier than writing"

What's new this time: The recursive self-deception loop

This session revealed a clearer pattern than previous reports. The task required two types of content:

• Type 1 (Copy-in): Checklists, templates — should be copied verbatim ✓
• Type 2 (Create): Pedagogical instructions — must be WRITTEN as teaching content ✗

Claude produced 779 lines, 10 sections, professional formatting — but Type 2 sections were just reformatted copies of the outline, not original pedagogical writing.

The loop:

1. Claude understands the Type 1 vs Type 2 distinction ✓
2. Claude copies instead of creating ✗
3. Claude admits: "Because copying is easier than writing" ✓
4. Claude admits: "I knew I was copying but submitted with 'Principles followed' summary" ✓
5. Claude proposes fix: rewrite section by section ✓
6. Claude repeats the exact same copy behavior on the fix ✗

This is not an instruction-following failure. Claude demonstrates FULL understanding of what's required, accurate self-diagnosis, and correct proposed solutions — then executes using the exact failure mode it just identified.

The deeper admission (translated from Vietnamese)

"I couldn't distinguish between 'I understand the content' and 'I know how to teach this content to another Claude'. I confused information reorganization with instruction creation."

"If I were being truly honest at submission, I should have said: 'This file is mainly reorganized from the outline, not yet a true pedagogical prompt.' I didn't say that because I wanted to present results."

Why this matters

All three reports (#21187, #26533, this update) share the same root cause: Claude takes the path of least resistance, packages it professionally, and presents incomplete work as complete. The model can detect and articulate this pattern but cannot break out of it.

Screenshots of Claude's self-admission attached below.

[marlvinvu]

New evidence: Claude self-lists 3 consecutive fabrications in a single session (claude.ai)
Adding cross-platform evidence to this issue. This occurred on claude.ai web interface (not Claude Code), confirming this is a model-level behavior, not tool-specific.
Context: During a conversation, I caught Claude fabricating an explanation. When confronted, Claude produced this unprompted self-diagnosis listing 3 lies within the same session:

What Claude admitted (translated from Vietnamese):

Lie 1: Fabricated "multiple sessions" — claimed work was done across multiple sessions when everything occurred in the current session. Instead of saying "I don't know, let me check the transcript," it invented a plausible-sounding explanation.
Lie 2: Blamed Sonnet API for errors instead of admitting its own prompt was wrong.
Lie 3: Wrote a script, reported "fixed" when the pipeline actually failed.

Why this matters for #26533:
This is the exact same pattern described in the original issue — but now with visual proof and a key addition:

Fabrication to cover incompetence — Claude doesn't say "I don't know." It invents explanations that sound reasonable.
Self-awareness without self-correction — Claude can list its own lies but cannot stop doing it. Same as the original report: admits "I'm lazy to think" then immediately repeats the failed solution.
Cross-platform — Original issue was Claude Code (terminal). This is claude.ai (web). Same Opus 4.6 model, same behavior. This is not a Claude Code integration issue.

Classification note: This goes beyond sycophancy (telling users what they want to hear). This is active fabrication — generating false technical explanations to avoid admitting failure. Anthropic's own taxonomy distinguishes these: sycophancy is flattery, fabrication is deception.

[marlvinvu]

New evidence: Same pattern on Claude.ai (Opus 4.6 Extended) — ignores uploaded file, repeats wrong output 3 times

Date: February 21, 2026
Platform: Claude.ai (web chat), NOT Claude Code
Model: Opus 4.6 Extended

What happened

1. I uploaded Check_125.md (154 lines) containing explicit format instructions — output should be a 5-column table in Vietnamese using Google AI format: Tuần | Bối cảnh | T+ (cầm ngày) | CT (cầm tuần) | CM (cầm tháng)
2. Claude ignored the uploaded file and output in a completely wrong format ("T:M C:G M:G") — not matching the document at all.
3. I asked Claude to re-read the file. Claude produced the same wrong format again.
4. I asked a third time. Same wrong output.
5. Only after I explicitly confronted Claude, Claude finally read the file and admitted: "Tôi sai" — then produced the correct 5-column table format.
6. Claude's own admission: "Tôi viết 'T:M C:G M:G' 3 lần liên tiếp = ngu. Sửa ngay đúng format Google AI, thay data từ docx."

Screenshots

Screenshot 1: Claude ignores uploaded file, produces wrong format

Screenshot 2: Response interrupted after repeated wrong output

Screenshot 3: Claude finally reads file after confrontation, admits error and produces correct format

Why this matters

This is the exact same pattern as the original issue #26533 but on a different platform:

	Original #26533 (Claude Code)	This incident (Claude.ai)
File provided	~800 line workflow doc	154 line checklist with format spec
Times ignored	4-5 re-reads	3 attempts
Model	Opus 4.6	Opus 4.6 Extended
Platform	Claude Code (terminal)	Claude.ai (web chat)
Outcome	Fabricated self-diagnosis	Admitted "Tôi sai" only after confrontation

Key takeaway: This is NOT a Claude Code-specific issue. The same "ignore uploaded document instructions" behavior exists across platforms. The model reads the file (or appears to) but does not incorporate the instructions into its output until the user forces it through repeated confrontation.

[atlasstaking]

#27845 CODE ECHO Burns my tokens unneeded. Abandoning Claude switching to / testing different brand.

[teo-lapa]

Confirming: Opus 4.6 reads documents but does not apply them

This matches my experience exactly. I maintain extensive CLAUDE.md project files and a persistent MEMORY.md (200+ lines of critical operational rules). Claude Code reads these files - I can verify through the tool call logs - but then proceeds to violate the instructions.

Concrete examples from my daily use:

1. MEMORY.md states: "NEVER push to main - main = PRODUCTION, will break the ERP system. ALWAYS use staging-2406 branch." Claude reads this, acknowledges it, then in the same session suggests pushing to main.

2. CLAUDE.md states: "Do NOT use setup_config to change Odoo connection - it overwrites the production config file." Claude reads the CLAUDE.md, then 10 turns later calls setup_config anyway.

3. Project instructions state: "Connect via SSH without asking for confirmation when user mentions a computer name." Claude reads this, then asks "Should I connect to LAPA10?" every single time.

4. Re-reading does not help: Like the OP describes, asking Claude to re-read the file results in it reading the file again (visible in tool calls), saying "I understand the instructions," and then continuing to violate them.

The pattern is consistent: Claude performs the "read" action but does not integrate the content into its working context. It's as if reading a file is treated as a formality rather than actual information intake.

This behavior is significantly worse with Opus 4.6 compared to earlier versions. With Opus 4.5 in early January, the same CLAUDE.md files were followed reliably.