Error Code Library

Match the error message, jump straight to the fix. Each card deep-links to symptoms, root cause, step-by-step repair, and prevention.

Prefer a printable list? Use the common errors cheat sheet or browse the troubleshooting library.

System & Access

Permission Denied / File Access

Jump to: macOS/Windows folder access, TCC prompts, and EACCES fixes.

macOSPermissions

Tool Execution Failed (127)

Jump to: command-not-found, nvm/Homebrew PATH, absolute-path fixes.

ShellPath

MCP Connection Failed

Jump to: dead MCP process, wrong port, VPN/firewall blocks.

MCPNetwork

Context & Logic

Context Window Exceeded

Jump to: 200K/1M token overflow, reset, and .coworkignore.

TokensLimits

Stale Context Warning

Jump to: forgotten instructions, re-read files, summarize-and-restart.

MemoryDrift

Hallucinated File Paths

Jump to: ENOENT paths, wrong src/, structure maps.

Hallucination

Workflow & Runtime

Git Merge Conflict Loop

Jump to: stop the loop, abort merge/rebase, manual resolve.

GitLoops

NPM Dependency Hell

Jump to: ERESOLVE, peer deps, clean install without --force.

NPMNode

Sub-Agent Timeout

Jump to: hung agents, stop conditions, lower parallelism.

AgentsTimeout

Rate Limit Exceeded (429)

Jump to: RPM vs TPD, backoff, throttle sub-agents.

APIBilling

How to use this library

Find the card whose title matches your message, then follow its jump notes. Every linked article uses the same structure: symptoms first, then root cause, a step-by-step repair, and prevention tips so the same failure does not come back tomorrow.

What the three categories mean

  • System & Access — the operating system refused something: a folder, a command, or a network connection. These are usually fixed by grants, paths, or restarts.
  • Context & Logic — Claude itself went wrong: ran out of room, drifted from instructions, or invented a path. These are fixed by resets, summaries, and tighter prompts, not by permissions.
  • Workflow & Runtime — the task machinery jammed: git loops, dependency conflicts, stalled agents, or rate limits. Each article names the specific unlock.

If your exact message is not listed

Do not leave empty-handed. Search the troubleshooting library with one distinctive word from the message, or open a category page linked in the headings above — they group related failures and near-misses. If the failure is genuinely new, the general fixing order in the troubleshooting hub still applies.

Two habits that make every fix faster

  • Keep the original message. Paste the full text into your notes before fixing — half the value is knowing exactly what was said.
  • Change one thing at a time. After each change, re-run the failing step. Two simultaneous changes make it impossible to know which one worked.