Fillet fail?

Rhino Rhino for Windows
1

I try cmd ‘Fillet Surface’ on these two corners https://c.mail.com/@651442177867522153/A8GAZS_fTfCKKDrfegU5Kg, …but no success? don’t understand why?
https://c.mail.com/@651442177867522153/uky5rJM5RjK1QCifAYvG9g

PS: using Rhino 5

Thanks folks

2

For solids you need to use FilletEdge instead of FilletSrf.
the first one allows you to select edges, as many as you want while FilletSrf only works by pairs of surfaces and need a bit of rework after.