Right so quick run down....
I'm in England, so EU server. I have used minion to install addons and it adds them to the default file dir "C:\Users\willt\Documents\Elder Scrolls Online\liveeu\AddOns\FoundryTacticalCombat"
Although my game is installed in dir "D:\Program Files (x86)\Zenimax Online" (A different drive) so I don't know if this effects how the game finds addons.
I have tried having the addon dir as both "\live\" and "\liveeu\" but doesn't seem to pick up on either, the only possible thing I can think of is that when i log into my PC my username on the log in screen is "Will Surname" instead of "willt" which is for some reason the name of the user folder in my file system. But the name of that folder is unchangeable.
If anyone can assist me or needs more details let me know