What This Error Means
npm ls reported ELSPROBLEMS because the installed dependency tree contains missing, invalid, or extraneous packages.
How to Fix It
Delete node_modules and reinstall (npm install or npm ci if you have a lockfile).
Run npm ls again and inspect the first reported problem.
If using workspaces, run install from the workspace root.
Why It Happens
node_modules is in a partially installed state.
A dependency was removed or changed without reinstalling.
Workspaces or symlinks are pointing at unexpected locations.
How to Verify
Run npm ls and confirm it completes without ELSPROBLEMS.
Run your build/test command to confirm runtime behavior.
Examples
npm ERR! code ELSPROBLEMS
t.equal(err.code, 'ELSPROBLEMS', 'should have ELSPROBLEMS error code')
t.equal(err.code, 'ELSPROBLEMS', 'should have error code')How npm executes the command
npm ls walks the installed dependency tree and compares it to expected metadata.
When it finds inconsistencies, it reports them as problems.
Prevention Tips
Use npm ci in CI for clean deterministic installs.
Avoid manually editing node_modules.
Keep lockfiles committed.
Where This Can Be Triggered
github.com/npm/cli/blob/417daa72b09c5129e7390cd12743ef31bf3ddb83/lib/commands/ls.js
Open-source npm CLI code reference tied to this error code. - GitHub
if (shouldThrow) {
throw Object.assign(
new Error([...problems].join('\n')),
{ code: 'ELSPROBLEMS' }
)
}
}