keras-team/keras · error · ValueError

Number of groups ({self.groups}) must be a multiple of the n

Error message

Number of groups ({self.groups}) must be a multiple of the number of channels ({dim}).

What it means

Error "Number of groups ({self.groups}) must be a multiple of the number of channels ({dim})." thrown in keras-team/keras.

Source

Thrown at keras/src/layers/normalization/group_normalization.py:123

        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})."
            )

        self.input_spec = InputSpec(
            ndim=len(input_shape), axes={self.axis: dim}
        )

        if self.scale:
            self.gamma = self.add_weight(
                shape=(dim,),
                name="gamma",
                initializer=self.gamma_initializer,
                regularizer=self.gamma_regularizer,
                constraint=self.gamma_constraint,
                autocast=False,
            )
        else:

View on GitHub (pinned to 7a34a03db6)

When it happens

Trigger: Thrown at keras/src/layers/normalization/group_normalization.py:123 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/f4bf442f39cc87be. Report an issue: GitHub.