I was trying to use the Weakaura that changes the layout based on raid size and kept getting the below Lua error. After some digging I discovered that the Cell options frame has the layout i'm using listed as "Default" while in the CellDB table (CellDB["layouts"] specifically) the layouts' name is "default" (lower case d). Changing the name of the layout to the lower case one in the Weakaura custom options made everything work as expected.

Not sure if this is by design or not or only Weakaura related?

10x Lua error in aura 'Cell auto-resize': Trigger 1
WeakAuras Version: 5.16.1
Aura Version: 2.0.0
Stack trace:
...aceCell/RaidFrames/Groups/SpotlightFrame.lua:759: attempt to index local 'layout' (a nil value)
[string "@Cell/RaidFrames/Groups/SpotlightFrame.lua"]:759: in function onEventFunc' [string "@Cell/Libs/CallbackHandler.lua"]:24: in function Fire'
[string "return function (e)"]:70: in function <[string "return function (e)"]:1>
[string "=[C]"]: in function xpcall' [string "@WeakAuras/GenericTrigger.lua"]:716: in function <WeakAuras/GenericTrigger.lua:625> [string "@WeakAuras/GenericTrigger.lua"]:897: in function ScanEventsInternal'
[string "@WeakAuras/GenericTrigger.lua"]:842: in function `ScanEvents'
[string "@WeakAuras/GenericTrigger.lua"]:1127: in function <WeakAuras/GenericTrigger.lua:1112>

Locals:
layout = nil
which = nil
width = nil
height = nil
(*temporary) = nil
(*temporary) = nil
(*temporary) = nil
(*temporary) = nil
(*temporary) = nil
(*temporary) = nil
(*temporary) = nil
(*temporary) = nil
(*temporary) = nil
(*temporary) = nil
(*temporary) = nil
(*temporary) = nil
(*temporary) = nil
(*temporary) = nil
(*temporary) = nil
(*temporary) = nil
(*temporary) = nil
(*temporary) = nil
(*temporary) = nil
(*temporary) = nil
(*temporary) = nil
(*temporary) = nil
(*temporary) = nil
(*temporary) = "attempt to index local 'layout' (a nil value)"
Cell =

{
MIN_DEBUFFS_VERSION = 228
MIN_QUICKASSIST_VERSION = 227
funcs = {
}
snippetVars = {
}
MIN_CLICKCASTINGS_VERSION = 239
IndentationLib = {
}
isRetail = true
animations = {
}
frames = {
}
MIN_INDICATORS_VERSION = 235
unitButtons = {
}
versionNum = 239
bFuncs = {
}
vars = {
}
hasHighestPriority = false
pixelPerfectFuncs = {
}
isVanilla = false
loaded = true
isTWW = true
version = "r239-release"
wowSupporters = {
}
menu = CellCascadingMenu {
}
supporters1 = {
}
MIN_LAYOUTS_VERSION = 239
supporters2 = {
}
L = {
}
defaults = {
}
MIN_VERSION = 220
iFuncs = {
}
uFuncs = {
}
isCata = false
isWrath = false
}
P = {
}
spotlightFrame = CellSpotlightFrame {
height = 85
width = 125
}
placeholders = {
1 = CellSpotlightFramePlaceholder1 {
}
2 = CellSpotlightFramePlaceholder2 {
}
3 = CellSpotlightFramePlaceholder3 {
}
4 = CellSpotlightFramePlaceholder4 {
}
5 = CellSpotlightFramePlaceholder5 {
}
6 = CellSpotlightFramePlaceholder6 {
}
7 = CellSpotlightFramePlaceholder7 {
}
8 = CellSpotlightFramePlaceholder8 {
}
9 = CellSpotlightFramePlaceholder9 {
}
10 = CellSpotlightFramePlaceholder10 {
}
11 = CellSpotlightFramePlaceholder11 {
}
12 = CellSpotlightFramePlaceholder12 {
}
13 = CellSpotlightFramePlaceholder13 {
}
14 = CellSpotlightFramePlaceholder14 {
}
15 = CellSpotlightFramePlaceholder15 {
}
}
menu = CellSpotlightAssignmentMenu {
BottomLeftCorner = Texture {
}
TopLeftCorner = Texture {
}
RightEdge = Texture {
}
height = 222
TopRightCorner = Texture {
}
Center = Texture {
}
TopEdge = Texture {
}
BottomEdge = Texture {
}
width = 123
BottomRightCorner = Texture {
}
LeftEdge = Texture {
}
backdropInfo = {
}
}
B = {
}
tanks = {
}
names = {
}
assignmentButtons = {
1 = Button {
}
2 = Button {
}
3 = Button {
}
4 = Button {
}
5 = Button {
}
6 = Button {
}
7 = Button {
}
8 = Button {
}
9 = Button {
}
10 = Button {
}
11 = Button {
}
12 = Button {
}
13 = Button {
}
14 = Button {
}
15 = Button {
}
}
NONE = "none"
tankUpdateRequired = nil
nameUpdateRequired = nil
anchorFrame = CellSpotlightAnchorFrame {
fadeOut = AnimationGroup {
}
height = 10
fadeIn = AnimationGroup {
}
width = 20
}