Whole warning message: “Warning: zone of type interior found between different solids! Material of cell zone x is aluminum, while material of cell zone y is steel. This will adversely affect the solution.” This message appears if you use a case file that has a surface with type ‘interior’ between two solid cell zones that have different solid material types. The warning has the following reason: the discontinuity in thermal conductivity where two different solid materials meet is treated more accurately if there is a wall/wall-shadow pair. When there is an interior face zone between the materials, harmonic averaging is used to evaluate the thermal conductivity at the face, which may result in a different conductive flux than what would be calculated at a coupled wall. This may or may not have a noticeable effect on the results, but the coupled wall treatment is always more accurate. This warning occurs when reading the .cas file but also when initializing the calculation. To solve it, type in the message window: (slit-interior-between-diff-solids) or /mesh/modify-zones/slit-interior-between-diff-solids