NSAccessibilityException ?
 

Looking at the log file for a smart update operation:
4 seconds after a "copy complete" that otherwise looks good, I see one final log file entry:

| 09:55:05 PM | Error | LOGGED EXCEPTION: NSAccessibilityException, reason: "AXSubrole" attribute unsupported by: <NSPanel: 0x9c655d0>, userInfo: {
NSAccessibilityErrorCodeExceptionInfo = -25205;
}

Is this a problem???

No. It's a program you're running probing our interface with the Accessibility API and generating an exception that doesn't affect copying (but gets logged).

OK thanks.
Interestingly, in the final log (I was running 3 consecutive scheduled backups and saw this error in the log file after first backup had completed while second one was underway), that error message was gone!

-CC