keras-team/keras · error · ValueError

Argument synchronized=True is only supported with the Tensor

Error message

Argument synchronized=True is only supported with the TensorFlow backend.

What it means

Error "Argument synchronized=True is only supported with the TensorFlow backend." thrown in keras-team/keras.

Source

Thrown at keras/src/layers/normalization/batch_normalization.py:185

        beta_initializer="zeros",
        gamma_initializer="ones",
        moving_mean_initializer="zeros",
        moving_variance_initializer="ones",
        beta_regularizer=None,
        gamma_regularizer=None,
        beta_constraint=None,
        gamma_constraint=None,
        renorm=False,
        renorm_clipping=None,
        renorm_momentum=0.99,
        synchronized=False,
        **kwargs,
    ):
        super().__init__(**kwargs)
        self.axis = int(axis)

        if synchronized and backend.backend() != "tensorflow":
            raise ValueError(
                "Argument synchronized=True is only supported "
                "with the TensorFlow backend."
            )
        self.synchronized = synchronized

        self.momentum = float(momentum)
        self.epsilon = float(epsilon)
        self.center = center
        self.scale = scale
        self.beta_initializer = initializers.get(beta_initializer)
        self.gamma_initializer = initializers.get(gamma_initializer)
        self.moving_mean_initializer = initializers.get(moving_mean_initializer)
        self.moving_variance_initializer = initializers.get(
            moving_variance_initializer
        )
        self.beta_regularizer = regularizers.get(beta_regularizer)
        self.gamma_regularizer = regularizers.get(gamma_regularizer)
        self.beta_constraint = constraints.get(beta_constraint)

View on GitHub (pinned to 7a34a03db6)

When it happens

Trigger: Thrown at keras/src/layers/normalization/batch_normalization.py:185 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/cdb75230f401932a. Report an issue: GitHub.