This just started happening after updating to v6.0.2 yesterday. 2011 15" MBP, 16GB, running 10.10.5. A compile error dialog came up, and neither typing Command-Period nor clicking the cancel button would dismiss the dialog. As a result of that I went to restart SD and the “Quit Script Debugger” menu item was greyed out, so I did a force-quit. Just now, I wasn’t even working in SD though it has been running most of the day, in attempting to double-check the version information of SD for this post, I’m seeing the same behavior - only the bottom 4 of 5 menu items in the Script Debugger menu are available, all others are greyed out. Various other menu items are greyed out as well - including “New Script” and almost all items on the View-Help menus. And I’m not seeing any unusual behavior in any other apps on this Mac. At this point I have no other data as far as what operations preceded this behavior and have.