I forgot to mention, in reply to your “memory crash” comment, that on my system if I allow the loop to continue for an extremely long time, UE editor will eventually crash with an out-of-memory error. This takes quite a while on my workstation because I have 64 GB RAM, but I’ve observed the crash more than once with that clearly being the error message. I also have watched Task Manager as the RAM footprint of UE slowly grows over time when this loop is running. There is clearly (to me, at least) a slow memory leak involved, but I believe that memory leak is secondary to the [nearly-]infinite loop caused by the cell size miscalculation.