1166x HeroLib\Class\Unit\Aura.lua:32: attempt to index local 'ThisSpell' (a nil value)
[string "@herolib\Class\Unit\Aura.lua"]:32: in function <HeroLib\Class\Unit\Aura.lua:27>
[string "=(tail call)"]: ?
[string "@herolib\Class\Unit\Aura.lua"]:81: in function BuffRemains' [string "@HeroLib\Class\Unit\Aura.lua"]:99: in function BuffUp'
[string "@herolib\Class\Unit\Aura.lua"]:104: in function BuffDown' [string "@HeroRotation_Priest\Shadow.lua"]:151: in function Condition'
[string "@HeroRotation\Commons.lua"]:62: in function CastCycle' [string "@HeroRotation_Priest\Shadow.lua"]:393: in function <HeroRotation_Priest\Shadow.lua:357> [string "@HeroRotation_Priest\Shadow.lua"]:603: in function ?'
[string "@HeroRotation\Main.lua"]:449: in function <HeroRotation\Main.lua:427>

Locals:
self =

{
CovenantID = defined @herolib\Class\Unit\Player\Main.lua:58
UseCache = true
ChiDeficitPercentage = defined @herolib\Class\Unit\Player\Power.lua:596
GCDStartTime = defined @herolib\Class\Unit\Player\Stat.lua:70
Race = defined @herolib\Class\Unit\Player\Main.lua:46
Insanityrain = defined @herolib\Class\Unit\Player\Power.lua:648
FocusLossOnCastEnd = defined @herolib\Class\Unit\Player\Power.lua:226
PainMax = defined @herolib\Class\Unit\Player\Power.lua:725
IsInVehicle = defined @herolib\Class\Unit\Player\Main.lua:124
IsInParty = defined @herolib\Class\Unit\Player\Main.lua:33
EnergyDeficit = defined @herolib\Class\Unit\Player\Power.lua:279
Fury = defined @herolib\Class\Unit\Player\Power.lua:698
InstanceInfo = defined @herolib\Class\Unit\Player\Instance.lua:22
RageDeficit = defined @herolib\Class\Unit\Player\Power.lua:139
VersatilityDmgPct = defined @herolib\Class\Unit\Player\Stat.lua:119
ArcaneChargesDeficitPercentage = defined @herolib\Class\Unit\Player\Power.lua:681
MaelstromPercentage = defined @herolib\Class\Unit\Player\Power.lua:554
ArcaneCharges = defined @herolib\Class\Unit\Player\Power.lua:666
IsInDungeonArea = defined @herolib\Class\Unit\Player\Instance.lua:53
ActiveMitigationNeeded = defined @herolib\Class\Unit\Player\Tank.lua:57
UpdateActiveLegendaryEffects = defined @herolib\Class\Unit\Player\Equipment.lua:141
SoulShardsDeficit = defined @herolib\Class\Unit\Player\Power.lua:470
GetEnemiesInRange = defined @herolib\Class\Unit\Player\Enemies.lua:53
IsInWhitelistedVehicle = defined @herolib\Class\Unit\Player\Main.lua:160
PainDeficit = defined @herolib\Class\Unit\Player\Power.lua:740
AttackPower = defined @herolib\Class\Unit\Player\Stat.lua:78
FocusCastRegen = defined @herolib\Class\Unit\Player\Power.lua:208
PainDeficitPercentage = defined @herolib\Class\Unit\Player\Power.lua:745
PrevOffGCD = defined @herolib\Events\Prev_Spell.lua:236
MasteryPct = defined @herolib\Class\Unit\Player\Stat.lua:114
InsanityPercentage = defined @herolib\Class\Unit\Player\Power.lua:633
ManaDeficitPercentageP = defined @herolib\Class\Unit\Player\Power.lua:113
FuryDeficit = defined @herolib\Class\Unit\Player\Power.lua:708
PrevGCD = defined @herolib\Events\Prev_Spell.lua:202
AstralPowerMax = defined @herolib\Class\Unit\Player\Power.lua:482
IsMounted = defined @herolib\Class\Unit\Player\Main.lua:28
EnergyRegenPercentage = defined @herolib\Class\Unit\Player\Power.lua:289
RunicPowerDeficit = defined @herolib\Class\Unit\Player\Power.lua:389
FuryPercentage = defined @herolib\Class\Unit\Player\Power.lua:703
Insanity = defined @HeroRotation_Priest\Overrides.lua:41
EnergyTimeToMaxPredicted = defined @herolib\Class\Unit\Player\Power.lua:336
ArcaneChargesPercentage = defined @herolib\Class\Unit\Player\Power.lua:671
AstralPowerDeficitPercentage = defined @herolib\Class\Unit\Player\Power.lua:503
MaelstromDeficitPercentage = define

This should be fixed as of commit 77e0f39

If the issue continues after applying that update, please let us know.