CheckMesh
 

Dear friends, I am getting following massage using CheckMesh command:
Please see the highlighted line (red color):

Do you know why this is happening?

Create time
Create polyMesh for time = 0
Time = 0
Mesh stats
points: 4851
faces: 12800
internal faces: 11200
cells: 4000
boundary patches: 5
point zones: 0
face zones: 0
cell zones: 0
Overall number of cells of each type:
hexahedra: 4000
prisms: 0
wedges: 0
pyramids: 0
tet wedges: 0
tetrahedra: 0
polyhedra: 0
Checking topology...
Boundary definition OK.
***Total number of faces on empty patches is not divisible by the number of cells in the mesh. Hence this mesh is not 1D or 2D.
Cell to face addressing OK.
Point usage OK.
Upper triangular ordering OK.
Face vertices OK.
Number of regions: 1 (OK).
Checking patch topology for multiply connected surfaces ...
Patch Faces Points Surface topology
topWall 80 105 ok (non-closed singly connected)
bottomWall 80 105 ok (non-closed singly connected)
leftWall 80 105 ok (non-closed singly connected)
rightWall 80 105 ok (non-closed singly connected)
frontAndBack 400 462 ok (non-closed singly connected)
Checking geometry...
Overall domain bounding box (0 0 0) (10 5 10)
Mesh (non-empty, non-wedge) directions (1 0 1)
Mesh (non-empty) directions (1 0 1)
All edges aligned with or perpendicular to non-empty directions.
Boundary openness (0 0 0) OK.
Max cell openness = 0 OK.
Max aspect ratio = 1 OK.
Minumum face area = 0.25. Maximum face area = 0.25. Face area magnitudes OK.
Min volume = 0.125. Max volume = 0.125. Total volume = 500. Cell volumes OK.
Mesh non-orthogonality Max: 0 average: 0
Non-orthogonality check OK.
Face pyramids OK.
Max skewness = 1.9984e-14 OK.
Coupled point location match (average 0) OK.
Mesh OK.
End

It is quite self-explanatory.
checkMesh first checks if the mesh is 1D or 2D.
Let me guess... you have a 3D mesh! :-)

I have solved my problem. I copied the problem and then changed the blockMeshDict file. So, when I did blockMesh, its not reading my present file (2D mesh). Finally I kill my present file and created a new blockMeshDict file. After that I found its working.

Thanks