keras-team/keras · error · ValueError

Layer {layer} supplied to Wrapper isn't a supported layer ty

Error message

Layer {layer} supplied to Wrapper isn't a supported layer type. Please ensure wrapped layer is a valid Keras layer.

What it means

Error "Layer {layer} supplied to Wrapper isn't a supported layer type. Please ensure wrapped layer is a valid Keras layer." thrown in keras-team/keras.

Source

Thrown at keras/src/layers/core/wrapper.py:20

from keras.src.layers.layer import Layer
from keras.src.saving import serialization_lib


@keras_export("keras.layers.Wrapper")
class Wrapper(Layer):
    """Abstract wrapper base class.

    Wrappers take another layer and augment it in various ways.
    Do not use this class as a layer, it is only an abstract base class.
    Two usable wrappers are the `TimeDistributed` and `Bidirectional` layers.

    Args:
        layer: The layer to be wrapped.
    """

    def __init__(self, layer, **kwargs):
        if not isinstance(layer, Layer):
            raise ValueError(
                f"Layer {layer} supplied to Wrapper isn't "
                "a supported layer type. Please "
                "ensure wrapped layer is a valid Keras layer."
            )
        super().__init__(**kwargs)
        self.layer = layer

    def build(self, input_shape=None):
        if not self.layer.built:
            self.layer.build(input_shape)
            self.layer.built = True

    def get_config(self):
        config = {"layer": serialization_lib.serialize_keras_object(self.layer)}
        base_config = super().get_config()
        return {**base_config, **config}

    @classmethod

View on GitHub (pinned to 7a34a03db6)

When it happens

Trigger: Thrown at keras/src/layers/core/wrapper.py:20 when the library encounters an invalid state.

Common situations: See trigger scenarios.

AI-assisted analysis of keras-team/keras@7a34a03db6 (2026-08-25). Data as JSON: /api/errors/c73a3c9fdb1c6aff. Report an issue: GitHub.