I’m having the same saving “…don’t have permissions” issues with an imported Rhino 5 (or 6) file. The Rhino file was 478MB(!), so if it’s related to file size, that is part of it. However, I’ve successfully imported MANY Rhino 5 and 6 files prior to the update this week and have been able to successfully Save All. Not now. Drives are nowhere near full (+90%capacity left).