Hi Keyur,

Thank you for the prompt reply. Yes I can open it in Fluen Meshing. The problem is that I can read the mesh using Fluent, perform computation, then save dat and cas. However, if I close the case and want to reopen the case using Fluent, it returns the error I mentioned in the original post. 

The "check" and "check the quality" reports are as follows. Could you please see if there is anything I can do? I do not want to read the mesh every time and then read the journal file to recover the case setup... Thank you very much. 

Domain extents.

x-coordinate: min = -7.617500e-02, max = 7.110600e-02.

y-coordinate: min = -2.358700e-02, max = 4.558700e-02.

z-coordinate: min = -1.885470e-01, max = 1.561000e-03.

Volume statistics.

minimum volume: 1.747063e-13.

maximum volume: 2.587584e-10.

total volume: 4.123249e-05.

Face area statistics.

minimum face area: 2.478286e-09.

maximum face area: 8.736383e-07.

average face area: 1.365562e-07.

Checking number of nodes per edge.

Checking number of nodes per face.

Checking number of nodes per cell.

Checking number of faces/neighbors per cell.

Checking cell faces/neighbors.

Checking isolated cells.

Checking face handedness.

Checking periodic face pairs.

Checking face children.

Checking face zone boundary conditions.

Checking for invalid node coordinates.

Checking poly cells.




Minimum Orthogonal Quality = 3.00263e-01

(To improve Orthogonal quality , use "Inverse Orthogonal Quality",

where Inverse Orthogonal Quality = 1 - Orthogonal Quality)



Maximum Aspect Ratio = 1.62759e+01