Have been getting the following a lot over the last few days on a couple of chars:

Message: C stack overflow
Time: Thu Sep 27 12:13:28 2018
Count: 5
Stack: C stack overflow
[C]: ?
[C]: ?
[C]: ?
[C]: ?
[C]: ?
[C]: ?
[C]: ?
[C]: ?
[C]: ?
[C]: ?
[C]: ?
[C]: ?
...
[C]: ?
[C]: ?
[C]: ?
[C]: ?
[C]: ?
[C]: ?
[C]: ?
[C]: ?
[C]: ?
[C]: ?

Locals: (*temporary) = NeuronActionButton25 {
0 =
flyoutborder = NeuronActionButton25FlyoutBorder {
}
class = "bar"
flyoutright = NeuronActionButton25FlyoutRight {
}
shine12 = NeuronActionButton25Shine12 {
}
shine11 = NeuronActionButton25Shine11 {
}
iconframefiller = NeuronActionButton25IconFrameFiller {
}
iconframebackground = NeuronActionButton25IconFrameBackGround {
}
__MSQ_Shine = NeuronActionButton25Shine {
}
shine7 = NeuronActionButton25Shine7 {
}
hitbox = NeuronActionButton25HitBox {
}
multiSpec = true
skinned = true
__MSQ_NormalSkin =

{
}
flyoutbordershadow = NeuronActionButton25FlyoutBorderShadow {
}
auracolor1 = {
}
macroColor = "1;1;1;1"
__MSQ_NormalHook = true
rangeInd = true
data = {
}
unit = "player"
tooltipsCombat = false
bindText = true
__MSQ_NormalTexture = {
}
upClicks = true
shine3 = NeuronActionButton25Shine3 {
}
dragbutton = "LeftButton"
barLockCtrl = false
SetNormalTexture = defined =[C]:-1
shine15 = NeuronActionButton25Shine15 {
}
cdAlpha = 1
UnwrapScript = defined @interface\FrameXML\SecureHandlers.lua:788
downClicks = false
barLockShift = true
highlighttexture = NeuronActionButton25HighlightTexture {
}
iconframecooldowntimer = NeuronActionButton25IconFrameCooldownTimer {
}
shine2 = NeuronActionButton25Shine2 {
}
cdcolor1 = {
}
autocastable = NeuronActionButton25AutoCastable {
}
__MSQ_Shape = "Square"
shine4 = NeuronActionButton25Shine4 {
}
editmode = false
hasAction = "Interface\AddOns\Masque_ElvUIesque\Textures\Normal"
manacolor = {
}
countColor = "1;1;1;1"
equipcolor = {
}
iconframe = NeuronActionButton25IconFrame {
}
flyoutarrow = NeuronActionButton25FlyoutArrow {
}
FlyoutBorder = NeuronActionButton25FlyoutBorder {
}
SetFrameLevel = defined =[C]:-1
macroname = NeuronActionButton25MacroName {
}
shine5 = NeuronActionButton25Shine5 {
}
shine1 = NeuronActionButton25Shine1 {
}
elapsed = 0.18100000917912
iconframeicon = NeuronActionButton25IconFrameIcon {
}
tooltips = true
__MSQ_Background = false
shine16 = NeuronActionButton25Shine16 {
}
UberTooltips = true
__MSQ_BaseFrame = {
}
spellGlowDef = true
gloss = NeuronActionButton25Gloss {
}
macroText = false
shape = "square"
iconframeaurawatchtimer = NeuronActionButton25IconFrameAuraWatchTimer {
}
shine13 = NeuronActionButton25Shine13 {
}
barLock = true
cdcolor2 = {
}
objType = "ACTIONBUTTON"
countText = true
__MSQ_NormalColor = {
}
debuffcolor = {
}
barLockAlt = false
__MSQ_FrameHook = true
macroshow = ""
macroparse = "
#showtooltip
/cast [@mouseOver,exists][@target,exists][@player] Penance
"
noAction = false
config = {
}
shine6 = NeuronActionButton25Shine6 {
}
showGrid = false
FlyoutArrow = NeuronActionButton25FlyoutArrow {
}
hotkey = NeuronActionButton25HotKey {
}
FlyoutBorderShadow = NeuronActionButton25FlyoutBorderShadow {
}
CDB = {
}
specdata = {
}
flyoutleft = NeuronActionButton25FlyoutLeft {
}
shine9 = NeuronActionButton25Shine9 {
}
iconframeaurawatch = NeuronActionButton25IconFrameAuraWatch {
}
pushedtexture = NeuronActionButton25PushedTexture {
}
iconframeflash = NeuronActionButton25IconFrameFlash {
}
auraText = false
auraInd = false
shine = NeuronActionButton25Shine {
}
objTIndex = 25
bindColor = "1;1;1;1"
shine10 = NeuronActionButton25Shine10 {
}
count = NeuronActionButton25Count {
}
bar = NeuronActionBar1 {
}
normaltexture = NeuronActionButton25NormalTexture {
}
spellID = 47540
Execute = defined @interface\FrameXML\SecureHandlers.lua:777
tooltipsEnhanced = true
border = Neuro

It's preceded by this:

Message: C stack overflow
Time: Thu Sep 27 12:08:27 2018
Count: 1
Stack: C stack overflow
(tail call): ?
[C]: ?
[C]: in function SetSpellByID' Interface\AddOns\Neuron\Neuron-Buttons.lua:2416: in function MACRO_SetSpellTooltip'
Interface\AddOns\Neuron\Neuron-Buttons.lua:2497: in function MACRO_SetTooltip' Interface\AddOns\Neuron\Neuron-Buttons.lua:2543: in function MACRO_OnEnter'
Interface\AddOns\Neuron\Neuron-Buttons.lua:3401: in function <Interface\AddOns\Neuron\Neuron-Buttons.lua:3401>
[C]: ?
[C]: ?
[C]: ?
[C]: ?
[C]: ?
...
[C]: ?
[C]: ?
[C]: ?
[C]: ?
[C]: ?
[C]: ?
[C]: ?
[C]: ?
[C]: ?
[C]: ?

Locals: (*temporary) = true
(*temporary) = defined =[C]:-1