neoclide/coc.nvim · error · Error

Unable to load extension at ${extensionRoot}, missing packag

Error message

Unable to load extension at ${extensionRoot}, missing package.json

What it means

Thrown by ExtensionManager.load() when loading a source-code extension whose root folder has no readable package.json, or the parsed JSON has no `name` field. coc.nvim requires a package.json manifest to identify and register an extension. It indicates the given extensionRoot does not contain a valid extension.

Source

Thrown at src/extension/manager.ts:655

      void window.showInformationMessage(`watching ${item.directory}`)
      client.subscribe('**/*.js', async () => {
        this.reloadExtension(id).then(() => {
          void window.showInformationMessage(`reloaded ${id}`)
        }, onUnexpectedError)
      })
    }
  }

  /**
   * load extension in folder or file
   */
  public async load(filepath: string, active: boolean, options?: ExtensionLoadOptions): Promise<ExportExtension> {
    let name: string
    if (options?.sourceCode) {
      let extensionRoot = options.extensionRoot ?? filepath
      let obj = loadJson(path.join(extensionRoot, 'package.json')) as any
      name = obj.name
      if (!name) throw new Error(`Unable to load extension at ${extensionRoot}, missing package.json`)
      await this.unloadExtension(name)
      await this.registerExtension(extensionRoot, obj, ExtensionType.Local, true, options)
    } else if (isDirectory(filepath)) {
      let obj = loadJson(path.join(filepath, 'package.json')) as any
      name = obj.name
      await this.loadExtension(filepath, true)
    } else {
      name = await this.loadExtensionFile(filepath, true)
    }
    if (!name) throw new Error(`Unable to load extension at ${filepath}`)
    let disabled = this.states.isDisabled(name)
    if (disabled) throw new Error(`extension ${name} is disabled`)
    let item = this.getExtension(name)
    if (active) await this.activate(name)
    return {
      get isActive() {
        return item.extension.isActive
      },

View on GitHub (pinned to 50e974d969)

Solutions

Ensure extensionRoot points to the directory containing a valid package.json with a `name` field
Verify package.json parses as valid JSON (`cat package.json | node -e 'JSON.parse(require("fs").readFileSync(0))'`)
Add or fix the `name` field in package.json
Check the path exists and is the extension root, not a subfolder

Example fix

// before
await coc.extensions.load('/path/to/ext/index.js', true, { sourceCode: true })
// after
await coc.extensions.load('/path/to/ext', true, { sourceCode: true }) // dir containing package.json

Defensive patterns

Strategy: validation

Validate before calling

const fs = require('fs');
const root = options?.extensionRoot ?? filepath;
const pkgPath = require('path').join(root, 'package.json');
if (!fs.existsSync(pkgPath)) throw new Error(`No package.json at ${root}`);
const pkg = JSON.parse(fs.readFileSync(pkgPath, 'utf8'));
if (!pkg.name) throw new Error(`package.json at ${root} has no name`);

Try / catch

try {
  await coc.extensions.load(filepath, true, { sourceCode: true });
} catch (e) {
  if (String(e.message).includes('missing package.json')) {
    // fall back or prompt user to fix extension root
  } else throw e;
}

Prevention

Always pass the extension root directory (containing package.json), not an entry file
Validate package.json name field before load
Run JSON.parse validation in CI for local extensions

When it happens

Trigger: Calling coc.extensions.load(filepath, active, {sourceCode: true}) where options.extensionRoot (default filepath) is a directory without package.json, or the package.json lacks a `name` field, or JSON.parse fails silently returning an object without name.

Common situations: Pointing load() at the source file instead of the project root; loading an extension folder that was never built/cloned fully; a malformed package.json; typo'd extensionRoot path.

Related errors

AI-assisted analysis of neoclide/coc.nvim@50e974d969 (2026-08-31). Data as JSON: /api/errors/7b6f5fe68afeaa35. Report an issue: GitHub.