Automattic/mongoose · error · TypeError

Schema for array path `${path}` is from a different copy of

Error message

Schema for array path `${path}` is from a different copy of the Mongoose module. Please make sure you're using the same version of Mongoose everywhere with `npm list mongoose`. If you are still getting this error, please add `new Schema()` around the path: ${path}: new Schema(...)

What it means

Error "Schema for array path `${path}` is from a different copy of the Mongoose module. Please make sure you're using the same version of Mongoose everywhere with `npm list mongoose`. If you are still getting this error, please add `new Schema()` around the path: ${path}: new Schema(...)" thrown in Automattic/mongoose.

Source

Thrown at lib/schema.js:1646

  let name;

  if (utils.isPOJO(type) || type === 'mixed') {
    return new MongooseTypes.Mixed(path, obj, null, this);
  }

  if (Array.isArray(type) || type === Array || type === 'array' || type === MongooseTypes.Array) {
    // if it was specified through { type } look for `cast`
    let cast = (type === Array || type === 'array')
      ? obj.cast || obj.of
      : type[0];

    // new Schema({ path: [new Schema({ ... })] })
    if (cast?.instanceOfSchema) {
      if (!(cast instanceof Schema)) {
        if (this.options._isMerging) {
          cast = new Schema(cast);
        } else {
          throw new TypeError('Schema for array path `' + path +
            '` is from a different copy of the Mongoose module. ' +
            'Please make sure you\'re using the same version ' +
            'of Mongoose everywhere with `npm list mongoose`. If you are still ' +
            'getting this error, please add `new Schema()` around the path: ' +
            `${path}: new Schema(...)`);
        }
      }
      return new MongooseTypes.DocumentArray(path, cast, obj, null, this);
    }
    if (cast &&
        cast[options.typeKey] &&
        cast[options.typeKey].instanceOfSchema) {
      if (!(cast[options.typeKey] instanceof Schema)) {
        if (this.options._isMerging) {
          cast[options.typeKey] = new Schema(cast[options.typeKey]);
        } else {
          throw new TypeError('Schema for array path `' + path +
            '` is from a different copy of the Mongoose module. ' +

View on GitHub (pinned to 49cdab0136)

When it happens

Trigger: Thrown at lib/schema.js:1646 when the library encounters an invalid state.

Common situations: See trigger scenarios.

AI-assisted analysis of Automattic/mongoose@49cdab0136 (2026-08-21). Data as JSON: /api/errors/9ee176e8c60ff356. Report an issue: GitHub.