Fix · Node, npm and build

Error: Cannot find module 'x'

What you may see

The app crashes at start with Cannot find module
It started after I pulled changes or moved files

Most likely cause

The package is not installed (or not listed in package.json), or the file path in the import is wrong.

Check first (about two minutes)

Is the name in quotes a package (like express) or a file path (like ./utils)?
For a package, check whether it appears in package.json and in node_modules.

The fix prompt

What you type here never leaves your browser. The search runs on this page, and nothing is sent to a server or to an AI.

The exact error or what you see

What you did before it happened

Kept only in this browser, on this device. Keys and passwords are removed before anything is saved.

Prompt language

You are a patient senior engineer who knows Node.js, npm and build tools and explains them to people who are not developers. I am not a developer, so explain every step in plain words and tell me exactly which button, menu or command you mean. If you are not sure about something, say so; do not guess.

THE PROBLEM
Error: Cannot find module 'x'

THE EXACT ERROR OR WHAT I SEE
[paste the exact error here]

WHAT I DID BEFORE IT HAPPENED
[write in a few words what you did before it happened]

MOST LIKELY CAUSE
The package is not installed (or not listed in package.json), or the file path in the import is wrong.

DO THESE STEPS, IN THIS ORDER
1. Find the import named in the error and tell me whether it is a package or a file.
2. For a package: check it is a REAL package name (AI tools sometimes invent names); if real, run npm install <name> so it is saved in package.json.
3. For a file: fix the path, the capital letters and the file extension that the project style needs.
4. Run the app again.
Stop and tell me if what you see does not match a step. Do not skip ahead.

CHECK THAT IT WORKED
- The app starts with no module error, and npm ls <name> shows the package.
Tell me exactly what I should see on the screen when it works.

DO NOT CHANGE
- Do not install a package you cannot find on the official package list.
- Anything I did not ask about: the design, the text, other pages, other settings or the data.
- Do not delete files, data or branches, do not reset or force-push, and do not rewrite history, unless you first show me exactly what would be lost and I say yes.
- Do not paste, print or ask me to paste a password or secret key into this chat. If one is needed, tell me which settings page of the right service to store it in.

WHEN YOU FINISH
Explain in simple words what you changed (file by file or setting by setting), why you changed it, and how I can undo it.

Paste it into Claude, ChatGPT, Gemini or Cursor, then follow what it says.

After you tried it, did it work?

Steps

Find the import named in the error and tell me whether it is a package or a file.
For a package: check it is a REAL package name (AI tools sometimes invent names); if real, run npm install <name> so it is saved in package.json.
For a file: fix the path, the capital letters and the file extension that the project style needs.
Run the app again.

Do not do this

Do not delete node_modules as the first step.
Do not install a package you cannot find on the official package list.

Try another entry