I recently did a clean OS install and had to reinstall minion. I found the 64 bit version would not find my addons no matter what I did. I installed the 32 bit version, and the problem was solved. No idea why. The OS I am using is very much 64 bit. Who knows.
EDIT: Also, if this is on a new computer or fresh install, run both the ESO launcher and the game, and then close them. That might help.
The 64 bit version is known to have bugs and the 32bit version is recommended even on a 64 bit OS.
Check www.esoui.com,forum, subforum "Minion", sticky thread at the top "Troubleshooting..."