Same problem here, force quit Rhino and after if I try exactly the same operation, it works.
With 5.2 WIP (5C146w) using the intersection command 
, I get almost always a Rhino block. Trying to isolate the problem I realized that the intersection can just hiding most (or all) objects NOT used to execute the command.
Software information
Software versions
Rhinoceros version: 5.2 WIP (5C146w)
IronPython version: 5.1.2015.131
Language: it (MacOS default)
OS X version: Versione 10.11.4 (Build 15E65)
Plug-ins
/Library/Frameworks/3DconnexionClient.framework/Versions/A/3DconnexionClient
Third party kernel extensions
com.3dconnexion.driver (10.2.5) 403007CA-7295-332E-9F17-DC3EA5DFD88D
Hardware information
Computer hardware
Hardware model: iMac13,2
Processor: Intel Core i5-3470 CPU @ 3.20GHz
Memory: 32 GB
Architecture: Intel 64 bit
Video hardware
Graphics: NVIDIA GeForce GTX 680MX 2048 MB
Memory: 2048 MB
Screen size: 2560 x 1440
Displays: iMac (109dpi 1x)
USB devices
Apple Inc.: FaceTime HD Camera (Built-in)
Apple Inc.: Bluetooth USB Host Controller
Inateck USB to SATA3 Bridge: Inateck Generic USB Device
Lexar: WorkflowD512
3Dconnexion: SpaceMouse Pro
Wacom Co.,Ltd.: CTH-460
Bluetooth devices
Apple: Apple Wireless Keyboard
Apple: Apple Wireless Trackpad
OpenGL information
OpenGL software
OpenGL version: 2.1 NVIDIA-10.10.5.2 310.42.25f01
Render version: 2.1
Shading language: 1.20
Maximum texture size: 16384 x 16384
Z-buffer depth: 24 bit
Maximum viewport size: 16384 x 16384
Implementation settings
Use texture compression: Yes
Appearance settings
Antialiasing: 4x
Mip map filtering: Nessuno
Anisotropic filtering: Nessuno
Intersect causing Rhino for Mac to freeze is ruining my life. Only figuratively, though. It’s 2016 and this thread started in 2014. Any hope?
Not as long as someone doesn’t come up with a reliable way to reproduce the issue.
I have a file that’s 73.8mb in size. Latest version of Mac OS and latest version of Rhino for Mac.
I have repeated this a few times. In this case, I am working on jewellery design to create rings with engravings using commands like move, copy, group, ungroup, hide, ShowSelected, lock, UnlockSelected, BlendCrv, ExtrudeCrv, split, UnrollSrf, join, ExtractSrf, NamedView, ViewCaptureToFile, DeleteHole and untrim. This is not an ordered list.
After a few minutes of work, when I run the intersect command Rhino freezes. I now save after every little bit of progress before running commands in Rhino for Mac.
I hope this helps to paint a picture.
Edit: My 13" MacbookPro is from 2010.
Unfortunately Rhino continues to have problems with the intersection command. It is a command that I use often. the big problem is that Rhino crashes forcing forced an exit that leads to losing your work in the last five minutes. Hoping to please everyone would like to propose my solution, waiting for the problem to be solved.
- before using the intersection command to cmd + S
- select the parts you want to use for the intersection and copy them with cmd + C
- will open a new blank file and paste the objects with cmd + V.
- use the intersection command.
- select the curves and the points obtained with the intersection, copying them with cmd + c, use cmd + ’ to return to the original file and paste the curves and points of intersection with the cmd + V.
The funny thing is why would MacRhino have a problem with Intersect where Windows Rhino doesn’t? What might be causing that? --Mitch
We are currently investigating a major memory leak during intersect in Rhino for Windows as well. Rhino for Mac would likely inherit this problem. This may be related (or perhaps not). Stay tuned.
We did find a memory leak in both Rhino for Mac and Rhino for Windows. We think we have a fix for this problem. We still don’t have a good model (or steps) to reproduce the issues that are being reported here, but hopefully the next RhinoWIP will have improvements. I’ll just echo Marlin…
The symptoms on each platform sound different, so it would be nice to have a way to check if this fix is working.
By using this command I can bring a lot of my comments.
The block usually occurs when there are many visible objects and the objects that have to intersect are in turn joined to other objects. What is certain is that as previously reported, copying and pasting objects into a new file. the intersection always manages.
Please test this issue in the latest RhinoWIP (5D92w) and see if it is any better. We patched up a long-standing memory leak that might account for this behavior.
i had it happen over the weekend… with maybe 3 weeks since the previous intersect freeze.
(posting as a bookmark… i’ll report back if i get another or i’ll report back in 6months if i don’t get a freeze 
)
Hi dan
The Rhino block (5D92w) , using the intersection command, which obliges to a forced output is still present. Unfortunately I can not publish or privately send the file to work with, but I will try to reproduce the problem in another way, so that you can make the necessary checks. As a long time, the problem occurs with many objects on the scene and randomly (in the sense that sometimes it works and sometimes it does not).
Ah, the worst kind of bug. Thanks for checking on this.
Hi Dan
it seems this old problem is back in the latest WIP…
it has been over 40min.
Rhino is frozen apart from a heavily delayed panning and View changes.
Escape does nothing.
this also happened with another file some days ago.
I think if I was to select just 2 object it would work fine .
so it’s a multiple selection that Rhino is not happy with [on my machine]
if I do Cmd Q it asks if I want to save, but it won’t quit.
I had to Force-Quit
nothing much in my file, just a few clean curves and un-trimed surfaces.
with thanks
akash
Can you please provide the file and steps to reliably reproduce this issue or is it still rather unpredictable?
Hi Dan
apology, I worked on on this part after restarting Rhino,
digging in the versions stack, I fished the part that created the latest freeze, and by it own in a new file it intesect instantaneously
copied that part back into the file and it’s fine,
so what ever happened seems not to be related to this specific file…?
so its in the unpredictable category unfortunately.
do you still want the file?
with thanks
akash
No thank you. Thanks for circling around on this.
Just adding something to this, I’m using the most recent Mac Rhino 5.5.5 on a new MacBook Pro 16" (fresh install, 2 days ago, with macOS Catalina 10.15.4) and the intersect froze on me too.
This is not exactly a new thing, as I always had the Intersect command freezing on me. I had this practice of saving the file right before an Intersect command, but I always thought it could be my old computers back then. I have two older Macs from 2013, running on Mojave and it was always a 50-50 thing to run the Intersect. Never predictable.
Luckily I didn’t lose the unsaved file this round, thanks to the autosave recovery. Just chiming in for what it’s worth, I hope this bug get squashed for good someday.
I had the intersect problem on V5 but I have not seen it on V6. I am convinced that this is an operating system problem.