Been using Rhino for over 20 years so pretty experienced. After upgrading to Release 7 a few months ago, I’ve been running into an issue where STP files or SLD files I’ve imported in from Solidworks have surface edges with inconsistent normals. At first, I chased this down one surface at a time but it’s like unraveling a sweater. Once I flip the normals of an errant surface, the next surface won’t join properly.
I’ve found that joining everything into a solid works but I have to join, then explode, and then join again for it to actually close properly.
Up until Release 7, I’ve never experienced this when working with solids and surfaces originally built in Solidworks.
I’m figuring out how to work around it (see above,) but something is amiss!