tensorflow/models · error · ValueError

Unknown block type {} for layer {}

Error message

Unknown block type {} for layer {}

What it means

Error "Unknown block type {} for layer {}" thrown in tensorflow/models.

Source

Thrown at official/vision/modeling/backbones/mobiledet.py:522

            in_filters=in_filters,
            out_filters=block_def.filters,
            kernel_size=block_def.kernel_size,
            strides=block_def.strides,
            input_compression_ratio=block_def.input_compression_ratio,
            output_compression_ratio=block_def.output_compression_ratio,
            activation=block_def.activation,
            use_residual=block_def.use_residual,
            kernel_initializer=self._kernel_initializer,
            kernel_regularizer=self._kernel_regularizer,
            bias_regularizer=self._bias_regularizer,
            use_sync_bn=self._use_sync_bn,
            norm_momentum=self._norm_momentum,
            norm_epsilon=self._norm_epsilon,
            divisible_by=self._get_divisible_by()
        )(net)

      else:
        raise ValueError('Unknown block type {} for layer {}'.format(
            block_def.block_fn, i))

      net = tf_keras.layers.Activation('linear', name=block_name)(net)

      if block_def.is_output:
        endpoints[str(endpoint_level)] = net
        endpoint_level += 1

    return net, endpoints, endpoint_level

  def get_config(self):
    config_dict = {
        'model_id': self._model_id,
        'filter_size_scale': self._filter_size_scale,
        'min_depth': self._min_depth,
        'divisible_by': self._divisible_by,
        'regularize_depthwise': self._regularize_depthwise,
        'kernel_initializer': self._kernel_initializer,

View on GitHub (pinned to e006f5f0d5)

Solutions

  1. Set the block 'type' field for the reported layer to a supported type such as 'conv' or 'inverted_bottleneck'.
  2. Check the block spec dict at the reported layer for a typo in the 'type' key.

When it happens

Trigger: Thrown at official/vision/modeling/backbones/mobiledet.py:522 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/8150c64ddfb5211b. Report an issue: GitHub.