>_ fix guides for AI-built apps
Your AI coding tool broke something.
Here's the actual fix.
Practical fixes and guides for people building with AI coding tools.
Start from what broke
Or start from your tool
Deploy & env vars
Works locally, breaks on deploy: missing env vars, build failures, production-only errors.
- Any AI tool Why the colors your AI coding agent wrote disappear the moment you build for production Published September 2026
- Any AI tool Why your AI-built app builds fine locally and fails the second you deploy it Published September 2026
- Replit Why your Replit fix never reaches your live app's database Published September 2026
- Bolt.new Your Bolt.new app crashed after deploy — the environment variable gap nobody warns you about Published August 2026
- Replit Why files your Replit app writes disappear after you redeploy Published July 2026
- Base44 Base44 auth breaks after deploy: 3 causes and fixes Published July 2026
- Replit Why your Replit app breaks the moment you deploy Published June 2026
Module not found
Imports that do not resolve, components that are missing, packages the tool invented.
- Bolt.new Why that npm package won't install in Bolt.new (it's not your code) Published September 2026
- v0 Your v0 component throws a Module-not-found error the second you paste it in — here's why Published August 2026
- Any AI tool Your AI coding agent just recommended a package that doesn't exist — here's why that's now a security risk Published July 2026
Connection & MCP
Servers that will not connect, MCP tools that never show up, timeouts.
Auth & API keys
Login broken after deploy, exposed or missing keys, 401s and 403s.
- Any AI tool Your Supabase app might be wide open, and nothing in your own testing would show it Published September 2026
- Any AI tool Your AI-built app might be leaking your API keys — here's how to actually check Published August 2026
- Base44 Base44 auth breaks after deploy: 3 causes and fixes Published July 2026
- Lovable Lovable app not saving data? The Supabase checklist Published June 2026, check for changes
Rules & context
Rules files ignored, instructions forgotten, files the agent cannot see.
- Claude Code Why Claude Code isn't following your CLAUDE.md file (it's probably never loaded) Published September 2026
- Claude Code Your Claude Code hook isn't firing (or isn't blocking anything) — here's why Published July 2026
- Cursor Cursor's agent doesn't know about a file that's clearly in your repo? Here's why Published July 2026
- Claude Code Why Claude Code stops following instructions you gave it earlier (it's not being stubborn) Published July 2026
- Cursor Cursor* ignoring your rules? Here's why (it's probably the .cursorrules migration) Published July 2026
Agent loops & reverts
Silent reverts, fix loops, agents rewriting what already worked.
- Any AI tool Why the colors your AI coding agent wrote disappear the moment you build for production Published September 2026
- Any AI tool Why your AI-built app builds fine locally and fails the second you deploy it Published September 2026
- Replit Why your Replit fix never reaches your live app's database Published September 2026
- Any AI tool Your AI agent didn't fix the bug: it fixed the test Published September 2026
- Cursor Why Cursor Agent mode burns through your requests way faster than you expect Published August 2026
- Lovable Lovable changed something you didn't ask it to touch — here's why and how to recover Published August 2026
- Cursor Cursor's agent stopped using some of your MCP tools — here's the 40-tool ceiling nobody warns you about Published August 2026
- Replit You rolled back your Replit Agent checkpoint — why the app is still broken Published August 2026
- Any AI tool Your AI coding agent just recommended a package that doesn't exist — here's why that's now a security risk Published July 2026
- Claude Code Your Claude Code hook isn't firing (or isn't blocking anything) — here's why Published July 2026
- Cursor Cursor's agent doesn't know about a file that's clearly in your repo? Here's why Published July 2026
- Any AI tool The AI Fix Loop: why your coding agent makes bugs worse (and how to break the cycle) Published July 2026
- Lovable How to fix Lovable applying your edit to the wrong component Published July 2026
- Cursor Cursor silently reverted my changes — here's the real fix Published July 2026
- Lovable Lovable app not saving data? The Supabase checklist Published June 2026, check for changes
- Base44 Base44 stuck on 'Thinking'? Here's how to get unstuck Published June 2026, check for changes
- Replit How to stop Replit Agent from rewriting code you didn't ask it to touch Published June 2026, check for changes
Rate limits & credits
429s and 529s, quotas, credit burn, files too large to read.
- Claude Code Why Claude Code missed code that's clearly in your file (it only read part of it) Published September 2026
- Cursor Why Cursor Agent mode burns through your requests way faster than you expect Published August 2026
- Claude Code Claude Code 529 errors and rate limits: how to tell which one you're hitting Published June 2026
- Base44 Base44 stuck on 'Thinking'? Here's how to get unstuck Published June 2026, check for changes
Data & database
Production data not updating, rollbacks out of sync, uploads that vanish.
- Replit Why your Replit fix never reaches your live app's database Published September 2026
- Any AI tool Your Supabase app might be wide open, and nothing in your own testing would show it Published September 2026
- Replit You rolled back your Replit Agent checkpoint — why the app is still broken Published August 2026
- Replit Why files your Replit app writes disappear after you redeploy Published July 2026
- Base44 Your Base44 app went blank after you changed a field — here's why Published July 2026
- Cursor Cursor* ignoring your rules? Here's why (it's probably the .cursorrules migration) Published July 2026
- Lovable Lovable app not saving data? The Supabase checklist Published June 2026, check for changes
Blank screens & broken UI
White screens after a change, one generation breaking another.
- Lovable Lovable changed something you didn't ask it to touch — here's why and how to recover Published August 2026
- Base44 Your Base44 app went blank after you changed a field — here's why Published July 2026
- Lovable Lovable preview is a blank white screen? Here's how to find the real error Published July 2026
Other fixes
Fixes that do not fit one failure mode yet.
No fix matches that yet. Try a shorter symptom, or browse every fix newest first. All fixes, newest first
Latest fixes
-
Why the colors your AI coding agent wrote disappear the moment you build for production
AI coding agents love to build Tailwind class names with template literals like bg-${status}-500. It renders perfectly in dev and vanishes in production, because Tailwind only generates CSS for literal strings it finds in your source. Here is why, and the fix.
Read the fix -
Why your AI-built app builds fine locally and fails the second you deploy it
Your coding agent writes an import whose casing doesn't quite match the filename. macOS and Windows don't care, so it works everywhere you test it. Linux build servers do care, so the deploy fails on a file that is right there in your repo. Here's the actual mechanism and the fix.
Read the fix -
Why your Replit fix never reaches your live app's database
Replit gives every app a separate development and production database, and the Agent can only write to the development one. Here is why a fix that works perfectly in your workspace can leave your live app broken, and what actually moves a schema or data change to production.
Read the fix