keras-team/keras · error · ValueError

input_tensor is not a Keras tensor; Received `input_tensor={

Error message

input_tensor is not a Keras tensor; Received `input_tensor={input_tensor}`

What it means

Error "input_tensor is not a Keras tensor; Received `input_tensor={input_tensor}`" thrown in keras-team/keras.

Source

Thrown at keras/src/applications/mobilenet_v2.py:162

            if backend.image_data_format() == "channels_first":
                if input_tensor.shape[1] != input_shape[1]:
                    raise ValueError(
                        "input_shape[1] must equal shape(input_tensor)[1] "
                        "when `image_data_format` is `channels_first`; "
                        "Received `input_tensor.shape="
                        f"{input_tensor.shape}`"
                        f", `input_shape={input_shape}`"
                    )
            else:
                if input_tensor.shape[2] != input_shape[1]:
                    raise ValueError(
                        "input_tensor.shape[2] must equal input_shape[1]; "
                        "Received `input_tensor.shape="
                        f"{input_tensor.shape}`, "
                        f"`input_shape={input_shape}`"
                    )
        else:
            raise ValueError(
                "input_tensor is not a Keras tensor; "
                f"Received `input_tensor={input_tensor}`"
            )

    # If input_shape is None, infer shape from input_tensor.
    if input_shape is None and input_tensor is not None:
        try:
            backend.is_keras_tensor(input_tensor)
        except ValueError:
            raise ValueError(
                "input_tensor must be a valid Keras tensor type; "
                f"Received {input_tensor} of type {type(input_tensor)}"
            )

        if input_shape is None and not backend.is_keras_tensor(input_tensor):
            default_size = 224
        elif input_shape is None and backend.is_keras_tensor(input_tensor):
            if backend.image_data_format() == "channels_first":

View on GitHub (pinned to 7a34a03db6)

When it happens

Trigger: Thrown at keras/src/applications/mobilenet_v2.py:162 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/d60b242a84a07b6b. Report an issue: GitHub.