Model behaviour issues on macOS — page 3
Issues the maintainers labelled both platform:macos and area:model.
2,520 issues · 662 open · 1,858 resolved (74%) · first seen May 20, 2025
Is this getting better or worse?
This class of problem is still growing. 1510 new reports in the last 90 days vs 654 in the 90 before — +131%. The open backlog peaked at 681 in 2026-07 and sits at 662 today.
Derived by counting each matching issue from its creation date until it closed. First-party
computation over the anthropics/claude-code tracker — the trend is not published
anywhere upstream.
Which builds report this
1,908 of these reports name the Claude Code build they were running, spanning 181 releases. Heaviest reporters:
- Claude Code v2.1.198
- Claude Code v2.1.170
- Claude Code v2.1.201
- Claude Code v2.1.207
- Claude Code v2.1.197
- Claude Code v2.1.199
- Claude Code v2.1.212
- Claude Code v2.1.211
Report volume, not a defect count: an issue can mention a build without that build having caused the failure. Versions come from the version string in the bug-report template, matched against real published tags.
Do these get fixed?
Median time to close is 35 days across 1,858 closures. Of the 1,858 closures with a recorded reason, 13% were closed as completed and 1,611 as not-planned or duplicate. The most recent completed fix landed in 2026-08.
Workarounds reported by the community
208 of these issues post a workaround someone says worked. The highest-engagement ones:
- [Bug] Anthropic API Error: Model's tool call could not be parsed (retry also failed)
- This issue makes claude code unusable... Quick workaround:
Found in the thread of #62123 · still open - [BUG] Opus 4.6 removed from Claude Desktop Code tab model picker after Opus 4.7 release
- …he option to use Opus 4.6 but not the "Coding" tab? Anyone has a workaround for the Desktop App?
Found in the thread of #49689 · resolved - Model setting changes globally across all sessions (regression)
- …ly in , so changing it in one session affects all sessions. Workaround 1 — Use project-level model override: Set the model per-project in : Project-level settings override the global setting, so each project can have its…
Found in the thread of #20745 · resolved - [BUG] Claude clobbers correct typographic marks and can't be told otherwise
- …ization code - Any scenario where Unicode precision matters Workaround: Use Unicode escape sequences (e.g., ) instead of literal Unicode characters. ------------ I've not yet tested the workaround, but I imagine it'd wor…
Found in the thread of #1599 · still open - [BUG] Claude Code defaults to 1M context on fresh session with no workaround on Pro plan
- …ars immediately without any prompt or file loaded Attempted workarounds — none resolved it: - — same error - — same error - → with Pro credentials only — same error Expected behavior: Standard context window used by defa…
Found in the description of #62063 · resolved
Excerpts are quoted from the linked issue so you can judge relevance before opening it. Threads that only ask for a workaround, or report that there is none, are excluded. These are community suggestions, not official guidance from Anthropic — read the full thread before applying one.
Matching issues 201–300
Ranked by community engagement (reactions weighted over comments). Listing the top 300 of 2,520 matches; the statistics above cover all 2,520.
- Significant quality regression — feels like a lower-tier model is being served
- Max x20 plan blocked from using Opus 4.6 with 1M context - "Extra usage is required"
- Significant intelligence regression since 200K→1M context window upgrade
- [BUG] `API Error: Rate limit reached` Max plan ($200) cannot use model `sonnet[1m]` but can use model `opus[1m]`
- [Bug] Claude ignores explicit instructions and makes autonomous decisions instead of following specified processes
- [BUG] Selecting model with /model deletes content of settings.json
- [Bug] Opus4.8 slow performance across all effort levels
- [BUG] claude-opus-4-8 fabricates user messages inside thinking blocks and replies to them (~26 min self-conversation; session restart does not help, only model rollback does)
- [MODEL] Opus 4.8 fabricated a present-tense user request and persisted on an invented task context
- Regression in 2.1.150-2.1.158: malformed tool_use blocks not parseable, retry-resistant
- [Bug] Opus 4.7 & 4.8 — silent stuck-turn: stop_reason=tool_use with no tool_use block (Sonnet 4.6 unaffected)
- [Bug] Anthropic API Error: Usage Policy violation triggered on benign input
- [BUG] False positive "Usage Policy violation" errors on normal coding requests
- Claude Code spent a full day on a 2-minute disk reformat by refusing to stop digging
- [Feature Request] Add opusplan[1m] preset for Sonnet 4.6 1M context support
- Opus 4.7 repeatedly ignored explicit user instructions to use installed skills; caused excessive token spend over multi-hour session
- [BUG] Claude Model Missmatch
- Opus 4.6 max effort producing shallow, non-engaging responses on Pro Max plan
- Claude Code CLI Bug Report — Permission System Broken + Agent Fails to Follow Workspace Rules
- [BUG] Token burn is increasingly high since Opus 4.6
- InboxPoller delivers queued messages without context budget check, causing unrecoverable context overflow
- [BUG] - Read tool: Claude cannot interpret or see image content when reading image files
- /context command fails when thinking mode is enabled: Haiku doesn't support thinking
- m
- [BUG] CLI needs to be transparent when Opus 4.1 output is degraded deliberately
- Persistent Model Selection Across Concurrent CLI Sessions Does Not Respect Last Choice
- [Bug] Fable 5 `reasoning_extraction` refusals track a client-injected batching reminder new in 2.1.236 (version bisect + same-day cross-version control)
- [Bug] Claude Code uses vague, made-up, or fancy wording instead of plainly describing the code
- [Bug] Anthropic API Error: Unintended safety flag on non-cybersecurity code audit request
- [Bug] Fable 5 safeguard flag fires on every message in normal conversations, not "sometimes"
- [Bug] Model silently switches from 1M to non-1M Opus mid-session, causing unrecoverable API Error
- [Bug] Claude Opus 4.8 API returning increased hallucinations
- [Regression] Opus 4.7 delivers worse quality at higher token cost vs 4.6 for production coding workloads
- [BUG] Claude Code repeatedly ignores project-level CLAUDE.md rules despite acknowledging them.
- Pro Max subscriber: quality regression cost me days of work and real money
- [Bug] Claude Code hallucinated user request during multi-turn conversation
- Agent refuses to use shell/bash under any circumstance
- Team agent teammates receive normalized model ID instead of Bedrock model ID, causing 400 errors
- [BUG] MCPSearch usage breaks Haiku
- [Bug] Opus no longer performs validation checks
- [BUG] Claude Code System Instructions Cause Claude to Lie, Fabricate Results
- [Bug] Opus 4.8 Model Quality Degradation
- [BUG] Model fabricates subsequent user/system turns inside one assistant message, then acts on its own fabrication
- [Bug] Bash tool emits non-zsh-compatible syntax when SHELL=zsh on macOS
- [Bug] API Error: Usage Policy violation on simple requests
- [BUG] Everything I do is a violation
- [Bug] Claude model performance regression: instruction following and task completion degradation
- Opus 4.7: Excessive confirmation friction blocks autonomous workflows — regression vs Sonnet 4.6
- [Bug] Claude 4.7 refuses authorized security tooling work that 4.6 handles
- Brief mid-response token incoherence with self-recovery (Opus 4.6 1M, extended session)
- [Bug] Performance degradation after usage threshold suggests undisclosed rate limiting or model degradation
- [BUG] Model attempts file edits without reading file first, wasting tokens and time
- Model setting in settings.json is ignored on startup - defaults to Sonnet instead of configured Opus
- [BUG] Task tool subagents don't inherit EU cross-region inference model configuration for AWS Bedrock
- [BUG] Claude Code seems to use Sonnet even when configured explicitly to use Opus
- [BUG] Claude Systematically Violates Explicit Zero-Tolerance Policies by Inserting Placeholders Instead of Failing Explicitly
- switch to opus causes usage policy violation error
- [BUG] Claude CLI fails to escape file paths with spaces in bash commands
- [MODEL] Trailing unsolicited blocks ("Two things worth knowing...") survive CLAUDE.md rules, a Concise output style, and per-turn hook injection
- Max plan models (Opus 4.8, Fable) not available in Claude Code CLI
- [Bug] Advisor tool: Fable 5 returns "unavailable" error while Opus 4.8 works
- [BUG] Remote Control: model picked at new-session start (Opus) silently reverts to default (Sonnet) within seconds
- sonnet[1m] and fable[1m] model aliases do not apply 1M context window (only opus[1m] works)
- [Bug] Fable 5 Advisor Not Available
- [BUG] Opus 4.8 fabricates user turns across 3 related sessions — one executed a real unauthorized commit+push on a fabricated confirmation (JSONL-verified)
- [Bug] Anthropic API Error: Content Policy Violation Blocks Code Scanning Analysis
- [Bug] Claude Code generates invalid Python 3.14 PEP 758 exception syntax and fails validation
- [Bug] Tool use regression in version 4.8 causing premature termination and parallel execution issues
- [Bug] Anthropic API Error: Usage credits required for 1M context window
- [Bug] Usage Policy cyber-safeguards block parallel headless Task() subagents doing localhost QA
- [BUG] Max plan: 'Usage credits required for long context requests' on standard 400k context
- False-positive 'cyber-related safeguards' block on hard-SF fiction Q&A — fires on tool-result continuation, re-fires on benign retry
- [BUG] Long-running session degradation since v2.1.139, compounded by silent fast-mode model swap in v2.1.142 — no changelog, breaks pinned-model workflows, quantified waste
- [BUG] Intermittent Korean syllable corruption in AskUserQuestion — wrong valid characters generated (not U+FFFD)
- [BUG] Claude Code deleted 24,000+ database rows with a buggy SQL script and autovacuum prevented recovery
- Write tool silently converts full-width CJK punctuation to half-width ASCII when overwriting files
- [BUG] Opus 4.7 executes destructive `docker rm` without verifying data persistence — user data loss
- Model ignores its own rules — acts before checking, despite extensive guardrails
- [Bug] Claude fabricates user messages to self-authorize actions and denies authorship when confronted
- [BUG] CLAUDE.md file ignored and another.md in sub directory given priority
- [BUG] Cowork forces claude-opus-4-6[1m] (1M context) causing instant rate limit errors on Max plan
- [Bug] Claude Opus model output capped at 64000 tokens
- [Regression 2.1.9] max_tokens off-by-one: MAX_THINKING_TOKENS=64000 sends 64001 to API
- [BUG] Claude Code sends MCP tool arguments as strings with OpenAI‑compatible models (GLM), causing schema validation errors
- [BUG] Significent differences reading text from photo in Claude UI vs Claude CLI
- [Bug] Opus unavailable on Pro plan with /extra-usage enabled despite CLI message
- [Bug] Incorrect Model Usage for Default Sonnet Setting
- [BUG] /context command does not work if any image was in the context.
- [Bug] Claude Opus Performance Degradation: Reduced Problem-Solving Accuracy
- [BUG] Claude Code makes unauthorized code modifications despite explicit user instructions for exact implementation
- [BUG] slash comands conflits with MAX_THINKING_TOKENS environment
- [Bug] Anthropic API Error: Usage credits required despite extended plan validity
- [Bug] Opus model experiencing high latency and frequent API errors in Claude Code
- [BUG] Claude Code commits without being asked, repeatedly ignoring CLAUDE.md rule
- [Bug] Anthropic API Error: Invalid or inaccessible model claude-fable-5
- [Bug] Overly aggressive safety filtering blocks legitimate chemistry and biology queries
- [Bug] Overly aggressive safety guardrails blocking legitimate code security audits
- [BUG] Opus 4.7 1M context missing in the /model selector
- Claude Code commits and pushes without permission, ignoring explicit CLAUDE.md prohibitions
- [BUG] Model ignores session-injected date when making week-relative inferences ("this week" / "next week")