Upon changing the talent in tier 2 to Horn of Winter i receive the following error message:
There are too many errors in your UI. As a result, your game experience may be degraded. Disable or update the failing addons if you don't want to see this message again.
This keeps repeating itself until i change back to another talenty in this tier.

This is the bug report, but I believe it is cut off:
33x Ovale\SpellBook-Spellbook.lua:524: attempt to compare number with nil Ovale\SpellBook-Spellbook.lua:524: in functionGetTimeToSpell'
Ovale\BestAction.lua:269: in function <Ovale\BestAction.lua:209>
(tail call): ?
Ovale\BestAction.lua:520: in function ?' Ovale\BestAction.lua:480: in functionRecursiveCompute'
Ovale\BestAction.lua:459: in function Compute' Ovale\BestAction.lua:922: in function?'
Ovale\BestAction.lua:480: in function RecursiveCompute' Ovale\BestAction.lua:459: in functionPostOrderCompute'
Ovale\BestAction.lua:420: in function Compute' Ovale\BestAction.lua:812: in function?'
Ovale\BestAction.lua:480: in function RecursiveCompute' Ovale\BestAction.lua:459: in functionPostOrderCompute'
Ovale\BestAction.lua:420: in function Compute' Ovale\BestAction.lua:812: in function?'
Ovale\BestAction.lua:480: in function RecursiveCompute' Ovale\BestAction.lua:459: in functionPostOrderCompute'
Ovale\BestAction.lua:420: in function Compute' Ovale\BestAction.lua:396: in functionGetAction'
Ovale\Frame.lua:212: in function `OnUpdate'
Ovale\Frame.lua:89: in function <Ovale\Frame.lua:88>

Locals:
state =

{
ConsumeRune = defined @ovale\Runes.lua:276
IsStance = defined @ovale\Stance.lua:182
GetTimeToSpell = defined @ovale\SpellBook.lua:497
class = "DEATHKNIGHT"
ApplyPowerCost = defined @ovale\Power.lua:668
isInitialized = true
ApplySpellAuras = defined @ovale\Aura.lua:1297
arcanecharges = 0
UpdateCounters = defined @ovale\Future.lua:949
DebugUnitAuras = defined @ovale\Aura.lua:1242
futureVariable = {
}
level = 110
hasteRating = 4930
counter = {
}
spellHaste = 15.169227600098
GetAuraByGUID = defined @ovale\Aura.lua:1465
GetRunesCooldown = defined @ovale\Runes.lua:346
stance = 0
specialization = 2
RuneCount = defined @ovale\Runes.lua:321
GetStateDuration = defined @ovale\State.lua:179
GetSpellCharges = defined @ovale\Cooldown.lua:517
insanity = 0
multistrike = 0
GetCD = defined @ovale\Cooldown.lua:419
RequireCooldownHandler = defined @ovale\Cooldown.lua:249
taggedEnemies = 0
DebugPower = defined @ovale\Power.lua:742
RequireHealthPercentHandler = defined @ovale\Health.lua:264
IsActiveAura = defined @ovale\Aura.lua:1273
activeEnemies = 0
Log = defined @ovale\State.lua:205
offHandWeaponDamage = 0
soulshards = 0
meleeCrit = 17.397142410278
nextCast = 1004110.015
multistrikeRating = 0
energy = 0
IsUsableSpell = defined @ovale\SpellBook.lua:453
agility = 7530
GetGCD = defined @ovale\Cooldown.lua:366
focus = 0
lastCast = {
}
alternate = 0
spellBonusDamage = 4000
powerRate = {
}
rangedCrit = 17.397142410278
PutState = defined @ovale\State.lua:185
mainHandWeaponDamage = 0
GetSpellHasteMultiplier = defined @ovale\PaperDoll.lua:479
GetMeleeHasteMultiplier = defined @ovale\PaperDoll.lua:467
GetSpellCooldown = defined @ovale\Cooldown.lua:474
RemoveAuraOnGUID = defined @ovale\Aura.lua:1536
chi = 0
GetPower = defined @ovale\Power.lua:356
spellCrit = 17.397142410278
GetMasteryMultiplier = defined @ovale\PaperDoll.lua:461
futureLastEnable = {
}
serial = 111
CheckSpellInfo = defined @ovale\Data.lua:458
meleeHaste = 28.989532470703
pain = 0
lastEnable = {
}
combatStartTime = 0
GetSpellCooldownDuration = defined @ovale\Cooldown.lua:481
ApplySpell = defined @ovale\Future.lua:1332
critRating = 4339
PowerCost = defined @ovale\Power.lua:376
AddAuraToGUID = defined @ovale\Aura.lua:1517
currentTime = 1004110.015
ApplyCooldown = defined @ovale\Cooldown.lua:323
baseDamageMultiplier = 1.0189499855042
GetRangedHasteMultiplier = defined @ovale\PaperDoll.lua:473
aura = {
}
GetSpellInfoProperty = defined @ovale\Data.lua:480
TimeToPower = defined @ovale\Power.lua:711
RequireBuffHandler = defined @ovale\Aura.lua:861
masteryEffect = 25.097141265869
isState = true
holy = 0
attackPower = 18365
IsChanneling = defined @ovale\Future.lua:1313
DebugCooldown = defined @ovale\Cooldown.lua:351
spellBonusHealing = 4000
GetDamageMultiplier = defined @ovale\Future.lua:897
GetCounterValue = defined @In`