Hello, can I know what this error means and how to get rid of it? I receive it when I click on generate mesh!
It means setting TOL_SNAP(0) = 0.0 is not recognized by the solver. Here the index is out of bounds, it should be 1,2 or 3, not 0 (zero). The question is how this keyword was set in the .mfx file. Can you please provide details about how you set the simulation up, did you edit the file outside the GUI, what version of MFiX are you using and the Operating System you are working on?
This is due to either the file being edited externally, or a bug in the MFiX GUI. As the “hint” in italic shows, you hit ‘delete’ to drop the problematic keyword. You should also be able to edit the offending line, but I see in your screenshot that feature is not implemented correctly - the line it’s showing is a comment line ## Cartesian grid
not the line with the error. I’ll fix that in the next release.
The setting for tol_snap in the GUI is here:
you can find this by using the 
tool in the top of MFiX screen.
I suggest clicking ‘Delete’ on that first popup, then using the “Snap Tolerance” to set the values you want (or accept the default of 0). That will get your project to load. But, as Jeff said, we’d really like to know how that TOL_SNAP(0) = 0 got in there, if it’s a bug we’ll fix it.