Stop the 'old_string is not unique' Error in Claude Code's Edit Tool — A Practical Rewrite Strategy
When Claude Code's Edit tool throws 'old_string is not unique in the file', the root cause is usually that the prompt didn't guarantee a uniquely identifiable target. Here's how to design rewrites that actually stick.
Upgraded to Claude Pro but Limits Haven't Changed — How to Diagnose and Fix It
Claude Pro or Max upgrade not reflecting? Learn how to diagnose whether payment completed, refresh your session, clear browser cache, and contact Anthropic support to get your plan unlocked.
When git add -A Sweeps Up .bak Backups — The Quiet Trap of In-Place Fix Scripts
How .bak backups left by sed -i and homegrown --fix scripts get silently swept into production by git add -A, why it is so easy to miss, and how scoped adds and .gitignore close the gap for good.
When Yesterday's Article Bleeds Into Today's — The Stale Fixed-Name Temp File Trap
In a Claude Code automation pipeline, a fixed-name temp file kept stale content from the previous run and leaked old body text into a completely different article. Here is why the write fails silently, and how unique names plus a post-write grep check prevent it.
When git push Says Success but Nothing Lands — the Silent commit Failure in Claude Code
git push prints Everything up-to-date and exits zero, yet your changes never reach the remote. Here is why commit silently fails on a fresh sandbox clone, and how to verify a real push with SHA comparison.
Claude Code Bash Tool Hangs on `npm run dev` and `docker run` — How to Handle Long-Running Processes
Claude Code's Bash tool freezes when running npm run dev, docker run, or other long-running processes. Learn background execution patterns, timeout strategies, and process management best practices.
When Claude Code Hooks Loop Forever — Stopping Self-Triggering PostToolUse Hooks
You wired up Claude Code hooks and now your terminal is a waterfall of tool calls that won't stop. Here's why PostToolUse hooks loop on themselves, and the patterns I use in real projects to make sure they never do again.
How to Fix Claude API 401 Invalid API Key Authentication Error
Complete guide to fixing Claude API 401 Invalid API Key errors. Covers environment variable issues, expired keys, OAuth token corruption, proxy interference, and more with step-by-step solutions.
Claude Giving Wrong or Unexpected Output? Here's How to Fix It
Claude's response doesn't match what you expected? This guide covers the most common causes of unexpected or wrong output—hallucinations, format issues, off-topic replies—and shows you exactly how to fix them.
Fix Claude Code Bash Tool Execution Errors — Timeouts, Permission Denied, and Truncated Output
Learn how to troubleshoot and fix Claude Code Bash tool errors including timeouts, Permission Denied, ENOENT, truncated output, and environment variable issues with step-by-step solutions.
How to Fix Claude API 429, 503 Errors and Timeouts: A Complete Troubleshooting Guide
Struggling with Claude API 429 rate limit errors, 503 service unavailable responses, or timeout failures? This guide covers root causes and step-by-step fixes including exponential backoff, concurrency control, and Tier upgrades.
Claude Not Responding or Freezing — How to Tell the Cause Apart and Fix It
A diagnosis-first guide to Claude not responding or freezing. Learn to split the problem into browser-side and API-side, decide when to wait, reload, or fix your code — with timeout and retry examples included.