tensorflow/models · error · ValueError

Unknown optimizer %s

Error message

Unknown optimizer %s

What it means

Error "Unknown optimizer %s" thrown in tensorflow/models.

Source

Thrown at official/legacy/image_classification/optimizer_factory.py:260

        learning_rate=base_learning_rate,
        beta_1=beta_1,
        beta_2=beta_2,
        epsilon=epsilon)
  elif optimizer_name == 'adamw':
    logging.info('Using AdamW')
    weight_decay = params.get('weight_decay', 0.01)
    beta_1 = params.get('beta_1', 0.9)
    beta_2 = params.get('beta_2', 0.999)
    epsilon = params.get('epsilon', 1e-07)
    optimizer = legacy_adamw.AdamWeightDecay(
        learning_rate=base_learning_rate,
        weight_decay_rate=weight_decay,
        beta_1=beta_1,
        beta_2=beta_2,
        epsilon=epsilon,
    )
  else:
    raise ValueError('Unknown optimizer %s' % optimizer_name)

  if params.get('lookahead', None):
    logging.info('Using lookahead optimizer.')
    optimizer = Lookahead(optimizer)

  # Moving average should be applied last, as it's applied at test time
  moving_average_decay = params.get('moving_average_decay', 0.)
  if moving_average_decay is not None and moving_average_decay > 0.:
    if model is None:
      raise ValueError(
          '`model` must be provided if using `ExponentialMovingAverage`.')
    logging.info('Including moving average decay.')
    optimizer = optimization.ExponentialMovingAverage(
        optimizer=optimizer, average_decay=moving_average_decay)
    optimizer.shadow_copy(model)
  return optimizer

View on GitHub (pinned to e006f5f0d5)

When it happens

Trigger: Thrown at official/legacy/image_classification/optimizer_factory.py:260 when the library encounters an invalid state.

Common situations: See trigger scenarios.

AI-assisted analysis of tensorflow/models@e006f5f0d5 (2026-08-24). Data as JSON: /api/errors/c6194466042a9341. Report an issue: GitHub.