System: Mac OS X 10.11.4 / Rhino 5.1
Uh-oh… The events immediately leading up to this: Launch Rhino. Open a file which I had finished up earlier this evening in order to get a quick render. I lazily resize the window to get a rough cropping, ZoomLens a bit, then open DocumentProperties and go to tweak the render resolution to a custom size. Without closing the settings window, I click back to the viewport and Render. Switch to Chrome for a minute while it does its thing, switch back, render looks fine so I save it as a JPEG. Recap: now there are three windows open, my 36mb .3dm, the DocumentProperties window, and the render output window. I didn’t modify the file in any way so instead of closing these individually I hit Command-Q to quit. Suddenly my geometry disappears and I get the alert shown. Uh-oh. I hit OK, and Rhino quits. Of course the next thing I’m going to try is opening up that file again, so I open Rhino, wait for it to start up, and then open the file from recent. Same alert, same empty looking file. It’s still 36mb. Here’s the output of Rescue3dmFile Analyze:
To find damaged parts of the file, search for the word "ERROR" in the following list. ====== FILENAME: /Users/ics/Projects/RS Winnetka 2016/CAD/Corrupted/Stairhall.3dm **ERROR** Read3dmStartSection() failed
Not too hard to spot the error.
Thankfully I’ve been keeping regular backups and so my workaround was as easy as restoring from the last time the file was modified (properly, by saving from Rhino). What I don’t have time for at the moment is determining exactly what changed between the files and more importantly what caused it. I have a copy of good file and the corrupted one– willing to share privately with anyone from McNeel if requested.