How to Fix Claude Cowork Common Errors (Cheat Sheet)

Published July 9, 2026 · Updated August 12, 2026

Use this page as a shareable error cheat sheet. Match the message you see, then deep-link into the full fix on CoworkHow — symptoms, root cause, step-by-step repair, and prevention.

Cowork sessions are cloud by default. Local folders, shell tools, browsers, and desktop apps still need Claude Desktop open and connected. Permission and PATH failures usually mean the desktop boundary failed — not that “everything stays only on your machine.”


Quick jump table

Error / symptomError articleTroubleshooting guide
Permission denied / cannot read folder / EACCESSystem & Access hubPermission Denied
Exit code 127 / command not foundTool Execution Failed (127)Exit Code 127
MCP connection failed / connection refusedSystem & Access hubMCP Connection Failed
Context window exceeded / request too largeContext & Logic hubContext Window Exceeded
Stale context / reverts earlier fixesStale Context WarningContext Window Exceeded
Hallucinated / wrong file paths (ENOENT)Hallucinated File PathsContext Window Exceeded
Git merge conflict loopGit Merge Conflict Loop
NPM ERESOLVE / peer dependency hellNPM Dependency Hell
Sub-agent timeout / partial agent resultsWorkflow & Runtime hubSub-Agent Timeout
Rate limit exceeded (429)Rate Limit ExceededSub-Agent Timeout (burst fan-out)

Full indexes: Error Code Library · Troubleshooting Library


1. Permission denied / “Claude can't read this folder”

Typical messages: Permission denied · Cannot read file at path… · Operation not permitted: EACCES · macOS “Grant access in System Settings → Privacy & Security → Files and Folders.”

What it means: Claude tried to touch a path outside the folders you allowed (or OS privacy settings blocked it). Cloud sessions and account-saved files are separate from Desktop folder access.

Fast fix: Move the file into an already-allowed workspace folder, or re-grant folder access in System Settings / app prompts, then restart Claude Desktop.

Deep dive: Permission Denied troubleshooting · Cloud vs Local Sessions · Security Model


2. Exit code 127 / command not found

Typical messages: Tool execution failed with exit code 127 · npm: command not found · python: command not found

What it means: The shell Cowork used could not find the binary on PATH. Interactive terminals (with nvm/pyenv/Homebrew from .zshrc) often differ from Cowork’s non-interactive environment.

Fast fix: Run which <tool> in your own terminal, then tell Claude the absolute path — or set a project env PATH with absolute directories (no ~).

Deep dive: Tool Execution Failed (127) · Exit Code 127 troubleshooting


3. zsh: permission denied: claude (executable bit / ownership)

Typical messages: zsh: permission denied: claude

What it means: The binary exists but lacks +x, or global npm directories are owned by root.

Fast fix:

chmod +x /path/to/claude
sudo chown -R $(whoami) $(npm config get prefix)/{lib/node_modules,bin,share}

Prefer fixing ownership over installing with sudo. Related: Permission Denied · Exit Code 127


4. MCP connection failed

Typical messages: Failed to connect to MCP server · Connection refused at localhost:… · MCP timeout

What it means: The MCP process is down, bound to a different port, or blocked by VPN/firewall. This is a local networking problem, not a model failure.

Fast fix: Confirm the process with lsof/netstat, match the port in Cowork settings, curl a health check, then retry after quitting and relaunching Desktop.

Deep dive: MCP Connection Failed · Skills and Connectors


5. Context window exceeded vs stale context

Hard limit messages: Request too large · Context window exceeded

Drift symptoms: Claude reverts earlier fixes, asks what file you were on, invents paths.

Fast fix for overflow: Reset/new chat, stop “read everything,” add .coworkignore, prefer search over bulk reads.

Fast fix for drift: Force a fresh file read, or summarize progress and start a new session with that summary.

Deep dive: Context Window Exceeded · Stale Context Warning · Context Loop Pattern · Hallucinated File Paths

Related reading


6. Workflow failures: git loops, npm hell, timeouts, 429s

FailureFast moveFull page
Merge conflict loopStop the agent → git merge --abort / rebase --abort → resolve manuallyGit Merge Conflict Loop
NPM peer / ERESOLVERead the conflict → clean install → pin compatible versions (avoid --force)NPM Dependency Hell
Sub-agent hangCap concurrency (≤5), add stop-after-N attemptsSub-Agent Timeout
429 rate limitIdentify RPM vs TPD; wait/backoff or reduce fan-outRate Limit Exceeded

Category hub: Workflow & Runtime Errors


FAQ

When I point Cowork at a working folder, what does that enable?

Desktop folder access lets Claude read/create/edit files there while Claude Desktop stays open and connected. Sessions are cloud-default and files can be saved to your Claude account. Do not assume folder contents never leave your machine. Check plan, org policy, retention, and training settings before using sensitive data.

What is the difference between Cowork and Claude Code?

Claude Code is a developer CLI in the terminal. Claude Cowork is Anthropic’s task mode for multi-step knowledge work (Desktop on macOS/Windows; web/mobile access depends on plan). Local folders, browsers, and desktop apps still need Desktop connected.

Where is the full error dictionary?

Error Code Library for every documented article, and Troubleshooting Library for the guided fix set.


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