neoclide/coc.nvim · error

errors[0]

Error message

errors[0]

What it means

In loadExtension (src/extension/manager.ts) the single-folder path calls loadExtensionJson(folder, workspace.version, errors), which accumulates problems (unreadable folder, bad JSON, engine/version mismatch) in the `errors` array. If any errors were collected, the first one is thrown verbatim as the exception message.

Source

Thrown at src/extension/manager.ts:322

    await Promise.resolve(item.deactivate())
  }

  /**
   * Load extension from folder, folder should contains coc extension.
   */
  public async loadExtension(folder: string | string[], noActive = false): Promise<boolean> {
    if (Array.isArray(folder)) {
      let results = await Promise.allSettled(folder.map(f => {
        return this.loadExtension(f, noActive)
      }))
      results.forEach(res => {
        if (res.status === 'rejected') throw new Error(`Error on loadExtension ${res.reason}`)
      })
      return true
    }
    let errors: string[] = []
    let obj = loadExtensionJson(folder, workspace.version, errors)
    if (errors.length > 0) throw new Error(errors[0])
    let { name } = obj
    if (this.states.isDisabled(name)) return false
    // unload if loaded
    await this.unloadExtension(name)
    let isLocal = !this.states.hasExtension(name)
    if (isLocal) this.states.addLocalExtension(name, folder)
    await this.registerExtension(folder, Object.freeze(obj), isLocal ? ExtensionType.Local : ExtensionType.Global, noActive)
    return true
  }

  /**
   * Deactivate & unregist extension
   */
  public async unloadExtension(id: string): Promise<void> {
    let item = this.extensions.get(id)
    if (item) {
      await this.deactivate(id)
      this.extensions.delete(id)

View on GitHub (pinned to 50e974d969)

Solutions

1. Read the thrown message — it is the first collector error — and fix that specific problem (usually the manifest)
2. Ensure the folder has a valid package.json with name, main and compatible engines
3. Check the extension's engines.coc version requirement against your coc.nvim version and upgrade/downgrade accordingly
4. Reinstall the extension from its source to restore a clean manifest

Example fix

// before: folder without manifest
await manager.loadExtension('~/.vim/my-ext') // throws errors[0]
// after: install properly so package.json exists
await manager.loadExtension('~/.vim/plugged/my-ext')

const pkgPath = path.join(folder, 'package.json')
if (!fs.existsSync(pkgPath)) throw new Error(`missing manifest: ${pkgPath}`)
const pkg = JSON.parse(fs.readFileSync(pkgPath, 'utf8'))
if (!pkg.name || !pkg.main) throw new Error(`incomplete manifest: ${pkgPath}`)

try {
  await manager.loadExtension(folder)
} catch (e) {
  logger.error(`loadExtension failed: ${e.message}`) // message is errors[0]
}

When it happens

Trigger: loadExtension(folder) where the folder lacks a valid extension manifest, the JSON cannot be parsed, or the extension declares engine/version requirements incompatible with the current workspace.version.

Common situations: Manually installing an extension folder without package.json; extension requiring a newer/older coc.nvim version; corrupt package.json after an interrupted install; pointing configuration at the wrong directory.

Related errors

• Error parsing JSON module ${cacheKey}: ${(e as Error).messag
• Error on loadExtension ${res.reason}

AI-assisted analysis of neoclide/coc.nvim@50e974d969 (2026-08-31). Data as JSON: /api/errors/0b16c190509746c1. Report an issue: GitHub.