face 0 in patch 1 does not have neighbour cell face: 4(7 0 8 15)
 

Hello All,
I am new to open foam and i am trying to generate a blockmesh but I am getting an error.
convertToMeters 1;

vertices
(
(0 0 0) //0
(0 0.23 0) //1
(0.1145 0.23 0) //2
(0.1145 0.3 0) //3
(0.1155 0.3 0)//4
(0.115 0.23 0) //5
(0.23 0.23 0) //6
(0.23 0 0) //7
(0 0 0.001) //8
(0 0.23 0.001) //9
(0.1145 0.23 0.001) //10
(0.1145 0.3 0.001) //11
(0.1155 0.3 0.001)//12
(0.115 0.23 0.001) //13
(0.23 0.23 0.001) //14
(0.23 0 0.001) //15


);

blocks
(
hex (0 7 6 1 15 14 9 8) (100 100 50) simpleGrading (1 1 1)
hex (5 4 3 2 13 12 11 10) (100 100 50) simpleGrading (1 1 1)


);

edges
(

);

boundary
(
inlet
{
type patch;
faces
(
(4 3 11 12)
);
}
outlet
{
type patch;
faces
(
(7 0 8 15)
);
}


frontAndBack
{
type patch;
faces
(
(0 1 4 7)
(2 3 4 5)
(15 8 9 14)
(13 10 11 12)
);
}
fixedWalls
{
type wall;
faces
(
(9 8 0 1)
(2 3 11 10)
(13 5 4 12)
(2 1 9 10)
(5 13 14 6)
(7 15 14 6)



);
}

);

mergePatchPairs
(
);

but i am have the following error
FOAM FATAL ERROR:
face 0 in patch 1 does not have neighbour cell face: 4(7 0 8 15)

From function Foam::labelList Foam::polyMesh::facePatchFaceCells(const faceList&, const labelListList&, const faceListList&, Foam::label) const
in file meshes/polyMesh/polyMeshFromShapeMesh.C at line 118.