npm · npm
The message
npm ERR! Invalid Version:
What it means
The version field in package.json is not valid semver, so npm cannot parse the package at all. It happens with a hand-edited value like 1.0 or v1.0.0 or an empty string, especially after a badly resolved conflict in that file. npm pkg set version=1.0.0 writes a proper three-part version back. The command edits only package.json and touches neither node_modules nor the lockfile, so every command that reads the file works again immediately afterwards.
The fix
npm pkg set version=1.0.0- Printed by
- npm
- npm
- 20
With npm the cause sits in the first code XXXX line rather than the last six npm ERR! lines, and when the failure comes from the dependency tree or a native build instead of your own code, deleting node_modules and installing again clears about half of them.
Reading an error message
- Read from the first line down. The lower you go the more it is about the tool’s internals; the cause is usually at the top.
- If there is a file and a line number, start there — not the top stack frame, but the topmost line that names a file you wrote.
- Search the message verbatim, but strip your own paths and variable names first; those are what stop the search from matching.
- The same condition is worded differently across tool versions. If results look wrong, add the version number to the query.
- Before pasting a fix, check what it throws away. Some of these cannot be undone.
Common questions
Q. What does “npm ERR! Invalid Version:” mean?
The version field in package.json is not valid semver, so npm cannot parse the package at all. It happens with a hand-edited value like 1.0 or v1.0.0 or an empty string, especially after a badly resolved conflict in that file. npm pkg set version=1.0.0 writes a proper three-part version back. The command edits only package.json and touches neither node_modules nor the lockfile, so every command that reads the file works again immediately afterwards.
Q. How do I fix it?
npm pkg set version=1.0.0 — before running it, check the explanation above for what this command discards.
Q. Which tool prints this?
npm. It sits under npm, and the message runs to 4 words.