Large mass planet collision errors

[SPopov6]

After running numerous two-layered, large mass planet collision simulations, a constant error that arose was due to segmentation fault (core dumped), around the time of impact. Switching to one-layered planets resolved the issue, but plotting each frame resulted in the planets suddenly not appearing in the designated box spaces. Is there any reason why this could be, or why the segmentation faults occur in the first place?