It is possible that there's a conflict between nUI and WIM that's causing the issue. If you edit [
Interface > AddOns > nUI > Integration > nUI_ChatFrame.lua ] with a plain text editor (like notepad) and look at the top of the file, you'll find the following...
Code:
local function reparentChatFrame()
local haveChatMod = (IsAddOnLoaded( "Prat" ) or IsAddOnLoaded( "Chatter" ));
change that as follows, save the file and reload to see if that makes the problem go away...
Code:
local function reparentChatFrame()
local haveChatMod = (IsAddOnLoaded( "Prat" ) or IsAddOnLoaded( "Chatter" ) or IsAddOnLoaded( "WIM" ));