I had this problem too and fixed it after reading this thread (thanks Canesfan). Here are the steps which worked for me:
(I am running Mac)
1. To uninstall Kies, I ran the 'dmg' file which I had downloaded last week (KiesMac_184.108.40.20623_10_1.dmg) That is the same file which was used to instal Kies just a week ago.
2. chose to uninstall Kies
3. Rebooted after uninstall
4. I then plugged in my phone (Note 2) and ran Android File Transfer, and it worked! first time.