How to Fix "npm ERR!" — ERESOLVE, E404, EACCES and More

npm ERR! is just a prefix on any npm failure — the actionable part is the code line right below it. Each code is a distinct family with a distinct fix, so read the code first: it tells you whether this is a dependency conflict, a script failure, a registry miss, a wrong directory, or a permissions problem.

ERESOLVE — peer dependency conflict

Since npm 7, peer dependencies are enforced strictly. npm ERR! code ERESOLVE ... unable to resolve dependency tree means two packages demand incompatible versions of a shared peer.

# pragmatic fix — install with npm 6-style peer handling
npm install --legacy-peer-deps

# proper fix — align the versions the conflict names
npm install react@18 react-dom@18

# persist it for the project if needed (.npmrc)
echo "legacy-peer-deps=true" >> .npmrc

ELIFECYCLE / "Missing script" — a script failed or does not exist

Either the scripts key is absent, or the command it runs exited non-zero.

# see the real script names
npm run

# "Missing script: build" -> add it to package.json "scripts"
# ELIFECYCLE errno 1 -> the real error is printed ABOVE this line, scroll up

E404 — package or version not found

A typo in the name, an unpublished version, or a private/scoped package without auth. npm ERR! 404 Not Found - GET https://registry.npmjs.org/<pkg>.

# check the real name and available versions
npm view express versions

# scoped/private package -> authenticate + point the scope at a registry
npm login
# .npmrc: @myorg:registry=https://your-registry/

ENOENT — a file or path is missing

Usually npm ran in a directory with no package.json: npm ERR! enoent ... open '/path/package.json'.

# run from the project root (the folder with package.json)
cd path/to/project
# starting fresh? create one first
npm init -y
# stale node_modules ENOENT:
rm -rf node_modules package-lock.json && npm install

EACCES — permission denied

npm cannot write, usually to a global directory owned by root from an earlier sudo install: EACCES: permission denied, access '/usr/lib/node_modules'.

# recommended: use a version manager so the global dir is user-owned
# (nvm / fnm), then reinstall globals without sudo

# or set a user-owned prefix
npm config set prefix ~/.npm-global   # add ~/.npm-global/bin to PATH

# repair ownership if needed
sudo chown -R $(whoami) ~/.npm

Quick diagnostic checklist

1. Read the npm ERR! code line first — it names the family and the fix path.
2. ERESOLVE? Read the "Conflicting peer dependency" block; try --legacy-peer-deps, then plan a version alignment.
3. Missing script? Run npm run with no arguments to list the real script names.
4. E404? Re-check the name with npm view <pkg>; confirm registry/auth for scoped packages.
5. ENOENT / EACCES? Confirm you are in the project root; fix directory ownership instead of using sudo.

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