Hi Michael, been tinkering on this end. Creating geometry in MOI and the ability to save it as a .3dm file has been restored. Repairing Permissions apparently did the trick. I downloaded an anti-virus app this evening and ran it to hunt down malware. There were 3 benign files. After rebooting, still unable to open AI, EPS and PDF files.

In the old days, these kinds of issues were resolved by dumping the application's preferences.

Unfortunately, I cannot use that newer machine - it's my partner's.

This is truly bizarre. MOI is the only application with issues.

Next, I will open MOI in another account on this machine to see if that works. That is not a convenient way to work. If that fails, I will try reinstalling the Mac OS.

Leonard