This is a known limitation in versions 2019R1 and 2019R2. The panel won’t be available when you have created a parallel poly-hexcore mesh inside the Watertight geometry workflow, with option “Enable parallel meshing” activated The command is available in serial, and you can save a mesh when working with Fluent Meshing standalone You can work around this issue by transferring the mesh into the solver, and exporting the case file