I'm experiencing problems with the serial library on Mac OS X machines - the XON/XOFF protocoll, which is required by the new bootloader, is not working as expected.
I'm doing some research on this problem ... But you can use the latest version 3 JAR also on Mac OS X except the firmware load function for the miniVNA tiny analyser!
If you want to update the firmware on the miniVNA tiny please use a Microsoft Windows (XP, VISTA, 7, 8, 8.1) based PC.
if you get a message from the OS X, that this developer is not valid, try to switch the App-Download permissions on the security tab in the system settings to "Mac App store and verified developers".