There is a problem with this selection that restarts the Toolkits back to the device selection screen. This is a bug on my part and has been fixed:
To fix the problem on your end go in to the Tools folder in the Toolkit and delete the following file:
Samsung Galaxy S3 Toolkit:
Samsung Galaxy Note 2 Toolkit:
Run the Toolkit and select your device and the Toolkit will force a download of the fixed device files. Problem fixed.