Get this error during the part of the quest where you balance a meter that pops up as extra UI frame. With Neatplates enabled, the UI frame is hidden and the following error message loops until the quest is completed or the addon is disabled:

3270x NeatPlates\NeatPlatesCore.lua:844: attempt to index local 'widget' (a nil value)
[string "@NeatPlates\NeatPlatesCore.lua"]:844: in function <NeatPlates\NeatPlatesCore.lua:834>
[string "@NeatPlates\NeatPlatesCore.lua"]:397: in function <NeatPlates\NeatPlatesCore.lua:380>
[string "@NeatPlates\NeatPlatesCore.lua"]:518: in function <NeatPlates\NeatPlatesCore.lua:508>
[string "@NeatPlates\NeatPlatesCore.lua"]:188: in function <NeatPlates\NeatPlatesCore.lua:161>

Locals:
widgetSetID = 282
widgetSet =

{
1 = {
}
2 = {
}
}
widgetID = 2222
widget = nil
(*temporary) = nil
(*temporary) = 2222
(*temporary) = nil
(*temporary) = nil
(*temporary) = nil
(*temporary) = nil
(*temporary) = nil
(*temporary) = nil
(*temporary) = "attempt to index local 'widget' (a nil value)"
unit = {
guid = "Creature-0-2084-2222-2177-159338-000075AB10"
isMouseover = false
class = ""
style = "NameOnly"
isMarked = false
rawName = "Hold the heat steady"
level = 51
alphaMult = 0.254902
red = 0
isInCombat = false
threatSituation = "LOW"
levelcolorRed = 1
powermax = 0
healthmax = 6100
health = 6100
unitid = "nameplate1"
isMini = false
isPet = false
isDangerous = false
name = "Hold the heat steady"
pvpname = "Hold the heat steady"
levelcolorBlue = 0
isBoss = false
isFocus = false
isTrivial = false
isTarget = false
levelcolorGreen = 0.820000
isTapped = false
type = "NPC"
blue = 0
power = 0
showName = true
reaction = "FRIENDLY"
green = 0.999998
isCasting = false
threatValue = 0
}
visual = {
customtext = {
}
highlight = {
}
eliteicon = {
}
powerbar = {
}
subtext = {
}
extrabar = {
}
focus = {
}
target = {
}
level = {
}
extraborder = {
}
castborder = {
}
spelltarget = {
}
healthbar = {
}
castbar = {
}
spelltext = {
}
threatborder = {
}
mouseover = {
}
spellicon = {
}
castnostop = {
}
durationtext = {
}
name = {
}
hitbox = {
}
extratext = {
}
healthborder = {
}
skullicon = {
}
raidicon = {
}
}