In Rhino for Mac 5.2.3 open a file from Rhino WIP (6) for Windows to be corrupted.
Here is a sample one.
Note that before opening a file you can’t easy tell if it comes from Rhino WIP (6) for Windows, unless you run Audit3dmFile. Or do you?
You will get a message similar to this one:
Click OK.
The file will open anyway but it is empty of course.

Now close the file.
Revert Changes, of course.
Another message like the first one, click OK.
Now note that size of the file decreases (in my example from 745 to 33 KB) and it is empty when you open it in Rhino WIP (6) for Windows.
I’m sure this corruption is new to Rhino for Mac (or to WinRhinoWIP, whoever is guilty). Not sure when it started occurring but definitely it wasn’t like that even a month or two ago.