Why DT reduced to DT_min but not trigger error report?

[MFiX_LYP]

But for rectangular domain, it don’t need geometry, just as jeff said. Is this file necessary for run simulation normally?

Error when meshing simple retangular cube

You don’t need to define a box as a geometry, just use the regular region, which is rectangular.

How this file generate? Is the file geometry_0001.stl generated when meshing? But when I meshing it not generated. And why this case can run in DMP without geometry_0001.stl file? Is this a bug?