keras-team/keras · error · ValueError

Received an invalid value for argument `value_dim`, expected

Error message

Received an invalid value for argument `value_dim`, expected a positive integer or `None`. Received: value_dim={value_dim}

What it means

Error "Received an invalid value for argument `value_dim`, expected a positive integer or `None`. Received: value_dim={value_dim}" thrown in keras-team/keras.

Source

Thrown at keras/src/layers/attention/multi_head_attention.py:150

        bias_constraint=None,
        use_gate=False,
        seed=None,
        **kwargs,
    ):
        if not isinstance(num_heads, int) or num_heads <= 0:
            raise ValueError(
                "Received an invalid value for argument `num_heads`, "
                f"expected a positive integer. Received: num_heads={num_heads}"
            )
        if not isinstance(key_dim, int) or key_dim <= 0:
            raise ValueError(
                "Received an invalid value for argument `key_dim`, expected "
                f"a positive integer. Received: key_dim={key_dim}"
            )
        if value_dim is not None and (
            not isinstance(value_dim, int) or value_dim <= 0
        ):
            raise ValueError(
                "Received an invalid value for argument `value_dim`, "
                "expected a positive integer or `None`. Received: "
                f"value_dim={value_dim}"
            )
        super().__init__(**kwargs)
        self.supports_masking = True
        self._num_heads = num_heads
        self._key_dim = key_dim
        self._value_dim = value_dim if value_dim else key_dim
        self._dropout = dropout
        self._use_bias = use_bias
        self._use_gate = use_gate
        if output_shape:
            if isinstance(output_shape, int):
                output_shape = (output_shape,)
            try:
                output_shape = tuple(output_shape)
            except:

View on GitHub (pinned to 7a34a03db6)

When it happens

Trigger: Thrown at keras/src/layers/attention/multi_head_attention.py:150 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/08dc178605b78b7e. Report an issue: GitHub.