There are some firewalls and anit-virus/spyware software that restricts individual software programs.  It could also be that something (firewall, anti-virus) is stopping Blacksmith3D from having access to write into it's AppData file. I'll have to check into exactly where that resides on a Mac and get back to you.

You are correct. That it's no reason for the software to be locking up. That is definitely a bug, and that will get fixed.