keras-team/keras · error · ValueError

Axis {self.axis} of input tensor should have a defined dimen

Error message

Axis {self.axis} of input tensor should have a defined dimension but the layer received an input with shape {input_shape}.

What it means

Error "Axis {self.axis} of input tensor should have a defined dimension but the layer received an input with shape {input_shape}." thrown in keras-team/keras.

Source

Thrown at keras/src/layers/normalization/group_normalization.py:107

        self.supports_masking = True
        self.autocast = False
        self.groups = groups
        self.axis = axis
        self.epsilon = epsilon
        self.center = center
        self.scale = scale
        self.beta_initializer = initializers.get(beta_initializer)
        self.gamma_initializer = initializers.get(gamma_initializer)
        self.beta_regularizer = regularizers.get(beta_regularizer)
        self.gamma_regularizer = regularizers.get(gamma_regularizer)
        self.beta_constraint = constraints.get(beta_constraint)
        self.gamma_constraint = constraints.get(gamma_constraint)

    def build(self, input_shape):
        dim = input_shape[self.axis]

        if dim is None:
            raise ValueError(
                f"Axis {self.axis} of input tensor should have a defined "
                "dimension but the layer received an input with shape "
                f"{input_shape}."
            )

        if self.groups == -1:
            self.groups = dim

        if dim < self.groups:
            raise ValueError(
                f"Number of groups ({self.groups}) cannot be more than the "
                f"number of channels ({dim})."
            )

        if dim % self.groups != 0:
            raise ValueError(
                f"Number of groups ({self.groups}) must be a multiple "
                f"of the number of channels ({dim})."

View on GitHub (pinned to 7a34a03db6)

When it happens

Trigger: Thrown at keras/src/layers/normalization/group_normalization.py:107 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/470b73eef408242a. Report an issue: GitHub.