15 August 2018
If you have saved the file as a .msh file, you will not be able to open the mesh file in ANSYS WorkBench Meshing. However, if you have saved your original mesh file as .mshdb, you should be able to open it up in Meshing to check your sizing settings.
If you have not manually changed the name of the case file while saving, Fluent (standalone session at least) uses the name of the mesh file as the case name. More often than not, we are used to changing the name while saving the case and data files. I generally create a new folder for each simulation run and have the respective mesh, case, and data files in there. This way I am reasonable sure of the mesh I used for my simulation.