keras-team/keras · error · ValueError

Expected `model` argument to be a Functional Model instance.

Error message

Expected `model` argument to be a Functional Model instance. Received: model={model}

What it means

Error "Expected `model` argument to be a Functional Model instance. Received: model={model}" thrown in keras-team/keras.

Source

Thrown at keras/src/models/cloning.py:375

            to build the model upon. If not provided,
            placeholders will be created.
        clone_function: callable to be applied on non-input layers in the model.
            By default, it clones the layer (without copying the weights).

    Returns:
        An instance of `Functional` reproducing the behavior
        of the original model, on top of new inputs tensors,
        using newly instantiated weights.
    """

    if not callable(clone_function):
        raise ValueError(
            "Expected `clone_function` argument to be a callable. "
            f"Received: clone_function={clone_function}"
        )

    if not isinstance(model, Functional):
        raise ValueError(
            "Expected `model` argument "
            f"to be a Functional Model instance. Received: model={model}"
        )

    if input_tensors is not None:
        if not all(
            isinstance(x, backend.KerasTensor)
            for x in tree.flatten(input_tensors)
        ):
            raise ValueError(
                "All entries in `input_tensors` must be KerasTensors. "
                f"Received invalid values: inputs_tensors={input_tensors}"
            )
        try:
            tree.assert_same_structure(input_tensors, model.input)
        except ValueError as e:
            raise ValueError(
                "`input_tensors` must have the same structure as model.input"

View on GitHub (pinned to 7a34a03db6)

When it happens

Trigger: Thrown at keras/src/models/cloning.py:375 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/ee9eebb41bce5fc3. Report an issue: GitHub.