How to model thin metal material layer

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As it says in the Input Output Reference, modeling thin highly conductive layers is not recommended. They can cause instabilities in the heat transfer model. Typically, such layers have little or no impact on the heat transfer or capacitance, only on the surface properties for solar and thermal absorptance. So you can

1. Model the layer as-is and see if any errors results.
2. Omit this layer
3. Omit this layer and change the absorptance properties of the next materiel layer to act as if it were coated with metal.