Filleting removing surfaces?

Can anyone tell me why when creating fillets on these edges, some of them remove surfaces? See screen shot.
Thanks in advance for any help.

The surface is probably still there but has gone “invisible” due to a bad trim… There are probably ways to repair this, but to be able to say for sure how, it would be best to post the model (just export the problem part).


Practice screwdriver.3dm (3.6 MB)

I just uploaded it. Thanks Mitch

Hello Richard, here you can see the problem. The radius of the main revolve is too small for the filletEdge you want to apply

Hi Diego and thanks for taking the time to reply. What is strange about this is that Im following a tutorial and following the specs in that tutorial to the exact measurement and using their recommended settings. Additionally, I used a .2 setting for the fillet. It works on most of the edges but creates problems on others? Filleting in general always seems to be problematic with the Mac version of Rhino 5? Im not why?