When CLAUDE.md rules are ignored, hooks never fire, or an MCP server shows no tools, the file usually didn't load, loaded from an unexpected location, or got overridden. This guide covers what the diagnostic entries (/context, /memory, /skills, /doctor, /mcp, and more) actually show, safe-mode bisection, and a table of six high-frequency error messages with fixes.
Work through install and login failures in five steps: verify PATH on your OS, confirm there is only one installation, test downloads.claude.ai for a 200, recover failed OAuth callbacks by pasting the login code or using claude auth login, then finish with claude doctor.
Five classes of runtime fixes: diagnose high memory with /compact plus /heapdump; recover a hung session with Ctrl+C and claude --resume; write large tables to files instead of forcing terminal output; escape autocompact thrashing by reading files in chunks or running /compact with a focus; fix broken search by installing system ripgrep and setting USE_BUILTIN_RIPGREP=0.
The official triage flow is seven commands and two minutes to a diagnosis. And the most common symptom — the assistant feeling limited or missing tools — is usually the tool profile: minimal allows only session_status, while coding is the default for new local configs.
The original Claude Code troubleshooting collection has been split into orders 33-35: installation & login, runtime problems, and config diagnosis. This page is their index.
Global skills live in ~/.claude/skills/, but they go missing in new sessions or the Desktop App? The problem usually isn't a missing file — it's that the skill descriptions aren't being loaded into context. This post clarifies the CLI vs Desktop App differences, the role of settings.json, and the most reliable fix.
When a RAG system breaks, 90% of the time it's one of these 10 failure modes. Identify which one first, then apply the matching fix — far more effective than optimizing blindly.