Wow... yup... that's nUI's casting bar, but I have never seen it so high in the interface. Really strange.
In any event, you should definitely be editing [
Interface > AddOns > nUI > Layouts > HUDLayouts > PlayerTarget > nUI_HUDSkin_PlayerTarget_Casting.lua ]
The section you want to edit is the following...
Code:
["Casting"] =
{
anchor =
{
anchor_pt = "BOTTOM",
relative_to = nUI_HUDLAYOUT_PLAYERTARGET.."Bottom",
relative_pt = "TOP",
xOfs = 0,
yOfs = 130,
},
The line highlighted in blue is the one that will move the player casting bar up and down.
If you are changing that 130 to 0 and saving the file, then do a '/nui rl' and the bar does not move at all then something is very wrong. I would suggest you search your system for the file "nUI_HUDSkin_PlayerTarget_Casting.lua" and see if you find more than one copy of it... maybe you're editing in the wrong path, I dunno.