Reply To: load coarse mesh data to a fine mesh
On not copying the “edges”: You may need to trigger an additional overlap communication as each process only updates its own local data with the (interpolated) values.
On the memory corruption: Did you maybe accidentally destruct the old lattice before / during interpolation? Seeing just the message I can only guess.
The decomposition will be the same if you use the default settings (which you do) and the same number of processes load balanced by the same load balancer.