I searched and searched, completely unable to find out how to fix it. Finally, today, I emailed the addon's creator, Grayhoof. Here's what he said:
When not in the game, delete the Proximo.lua file from your saved variables folder. It should be in:I tried it, and it worked! Special thanks to Grayhoof for personally responding to my inquiry. The world needs more people like you. :-)
C:\Program Files\World of Warcraft\WTF\Account\ACCOUNT_NAME\SavedVariables
For those of you who don't know, Proximo is an addon that helps you in arenas. It gives you a frame (shown above), that gets populated with your opponents. Whenever you, or anyone on your team with Proximo installed, hovers over or targets an enemy in an arena, that enemy gets added to the list. You can then select any enemy by clicking on his/her name in the Proximo window.