invoke-ai/InvokeAI · error · ValueError

The Component Source VAE is incompatible with the selected t

Error message

The Component Source VAE is incompatible with the selected transformer. TI2V-5B requires the 48-channel Wan 2.2 VAE; A14B models require the 16-channel Wan 2.1 VAE.

What it means

When the VAE is derived from the Component Source, _validate_component_source_vae compares the source's variant against the main transformer variant. Wan 2.2 TI2V-5B needs the 48-channel VAE while A14B models need the 16-channel Wan 2.1 VAE; if main_is_ti2v != source_is_ti2v the pair is incompatible and invoke() raises this ValueError.

Source

Thrown at invokeai/app/invocations/wan_model_loader.py:335

        if source_config.base != BaseModelType.Wan or source_config.type != ModelType.Main:
            raise ValueError("The Component Source model must resolve to a Wan main model.")
        if source_config.format != ModelFormat.Diffusers:
            raise ValueError(
                f"The Component Source model must be in Diffusers format. "
                f"The selected model '{source_config.name}' is in {source_config.format.value} format."
            )

    @staticmethod
    def _validate_component_source_vae(
        context: InvocationContext, model: ModelIdentifierField, main_variant: WanVariantType
    ) -> None:
        WanModelLoaderInvocation._validate_component_source_format(context, model)
        source_config = context.models.get_config(model)
        source_variant = getattr(source_config, "variant", None)
        main_is_ti2v = main_variant == WanVariantType.TI2V_5B
        source_is_ti2v = source_variant == WanVariantType.TI2V_5B
        if main_is_ti2v != source_is_ti2v:
            raise ValueError(
                "The Component Source VAE is incompatible with the selected transformer. "
                "TI2V-5B requires the 48-channel Wan 2.2 VAE; A14B models require the 16-channel Wan 2.1 VAE."
            )

    @staticmethod
    def _validate_standalone_vae(
        context: InvocationContext, model: ModelIdentifierField, main_variant: WanVariantType
    ) -> None:
        vae_config = context.models.get_config(model)
        if vae_config.base != BaseModelType.Wan or vae_config.type != ModelType.VAE:
            raise ValueError("The VAE must resolve to a standalone Wan VAE model.")
        expected_channels = 48 if main_variant == WanVariantType.TI2V_5B else 16
        if vae_config.latent_channels != expected_channels:
            raise ValueError(
                "The standalone VAE is incompatible with the selected transformer. "
                "TI2V-5B requires the 48-channel Wan 2.2 VAE; A14B models require the 16-channel Wan 2.1 VAE."
            )

View on GitHub (pinned to 0b6a024f2f)

Solutions

Match the Component Source variant to the transformer: use a TI2V-5B source for TI2V-5B, an A14B source for A14B
Set an explicit standalone 'VAE' with the correct latent channels (48 for TI2V-5B, 16 for A14B) instead of relying on Component Source
Swap the main transformer to the variant matching the component source you already have

Example fix

// before: TI2V-5B transformer with A14B component source
component_source=ModelIdentifierField(key='wan21-a14b-main', submodel_type=SubModelType.Transformer)
// after
component_source=ModelIdentifierField(key='wan22-ti2v-5b-main', submodel_type=SubModelType.Transformer)

Defensive patterns

Strategy: validation

Validate before calling

main_cfg = context.models.get_config(invocation.model)
src_cfg = context.models.get_config(invocation.component_source)
main_ti2v = getattr(main_cfg, 'variant', None) == WanVariantType.TI2V_5B
src_ti2v = getattr(src_cfg, 'variant', None) == WanVariantType.TI2V_5B
if main_ti2v != src_ti2v:
    raise ValueError('Component Source variant must match transformer variant (TI2V-5B vs A14B)')

Type guard

def variants_match(main_cfg, src_cfg) -> bool:
    main_ti2v = getattr(main_cfg, 'variant', None) == WanVariantType.TI2V_5B
    src_ti2v = getattr(src_cfg, 'variant', None) == WanVariantType.TI2V_5B
    return main_ti2v == src_ti2v

Try / catch

try:
    output = invocation.invoke(context)
except ValueError as e:
    if 'Component Source VAE is incompatible' in str(e):
        invocation.component_source = select_source_matching_variant(main_variant)

Prevention

Keep Wan 2.1 and Wan 2.2 components in separate workflows
Check the variant label on both transformer and component source before wiring
Prefer explicit standalone VAE overrides with the correct channel count over implicit sources

When it happens

Trigger: invoke() where main model variant is TI2V-5B but the Component Source is a non-TI2V (A14B) Wan model, or vice versa.

Common situations: Mixing Wan 2.1 A14B components with a Wan 2.2 5B transformer (or the reverse); a workflow built for one Wan generation reused with the other's component source.

Related errors

AI-assisted analysis of invoke-ai/InvokeAI@0b6a024f2f (2026-08-29). Data as JSON: /api/errors/51ffc659caa25dd7. Report an issue: GitHub.