File constant/polyMesh/boundary must be edited. First remove empty patches, rename non-empty patches and edit their properties^14.4:

3
(
    solid_hub
    {
        type            wall;
        nFaces          696;
        startFace       563313;
    }
    solid_shroud
    {
        type            wall;
        nFaces          955;
        startFace       564009;
    }
    solid_rotor_blade
    {
        type            mappedWall;
        sampleMode      nearestPatchFace;
        sampleRegion    rotor;
        samplePatch     rotor_blade;
        offsetMode      uniform;
        offset          (0 0 0);
        nFaces          74820;
        startFace       564964;
    }
)

Patch solid_rotor_blade is adjoining rotor region and is of type mappedWall because heat transfer from the fluid to the solid and vice versa is assumed. Patches solid_hub and solid_shroud are standard wall.