well i did that before. i even deleted all add-ons and renaming and i deleted the WTF folder also. but when i installed it it looks fine but as soon as i quit the game and log back in only on 1 character it ask me to install it and nothing happens once i click on it (well it loads the ui but then the install screen is still there). the only way i can get rid of that is deleting LUI in the saved variables on that characters profile. I'm debating on doing a WoW reinstall but thats gonna be a pain. lol
Problems like that are best fixed by doing a clean install:
Delete or Rename your WTF entirely.
Load the game.
I just spent the last hour trying to get this to happen to a clean install by having various addons enabled or disabled or outright not present.
I've tried to open the LUI options and ignoring the Install button, but it turns out the options cannot be opened until it's installed.
I tried to force LUI to set a different profile and then click Install, which could potentially corrupt the profile of that other character when they log on, it didn't even do that.
I tried this on all 8 characters I have in case it's something that's character specific!
I really can't reproduce any of this. If the issues is about profiles, a clean install sounds like a good last ditch effort to fix this once and for all. It also prevent any kind of data corruption that may have happened from carrying information all the way from Wrath.
Edit: Just went on my druid, installed just fine. Deleted my Rogue's profile, then logged back on my rogue and tried to set it back to the newly recreated profile by her name. The bugsack sound happened during load screen but it's practically gibberish and fixed itself when everything loaded. (But if someone still need to know, it's was about "attempt to index "Minimap", a nil value" saying Minimap shouldn't exist -at all-)