Mousing over

G[593]='SP K0460 L001 N255 A:2530 T:2530 P:B592+K10003912 E31727'

gives the error

Date: 2020-02-12 16:33:32
ID: 1
Error occured in: Global
Count: 6
Message: ..\AddOns\Wholly\Wholly.lua line 2653:
bad argument #3 to 'format' (string expected, got nil)
Debug:
[C]: ?
Wholly\Wholly.lua:2653: _PrettyQuestString()
Wholly\Wholly.lua:3204: func()
Grail\Grail.lua:8495:
Grail\Grail.lua:8456
(tail call): ?
Wholly\Wholly.lua:3170: _QuestInfoSection()
Wholly\Wholly.lua:3008: _PopulateTooltipForQuest()
Wholly\Wholly.lua:1306: ButtonEnter()
[string ":OnEnter"]:1:
[string ":OnEnter"]:1
Locals:
(*temporary) = "|c%s%s [%s]"
(*temporary) = "FFFF0000"
(*temporary) = nil
(*temporary) = "Item"
(*temporary) = "string expected, got nil"

AddOns:
Swatter, v8.2.6511 (SwimmingSeadragon)
AdvancedInterfaceOptions, v1.3.3
AucAdvanced, v8.2.6471 (SwimmingSeadragon)
auccheapsearcher, v20190917r3
AucFilterBasic, v8.2.6497 (SwimmingSeadragon)
AucStatHistogram, v8.2.6499 (SwimmingSeadragon)
AucStatiLevel, v8.2.6503 (SwimmingSeadragon)
AucStatPurchased, v8.2.6500 (SwimmingSeadragon)
AucStatSimple, v8.2.6501 (SwimmingSeadragon)
AucStatStdDev, v8.2.6502 (SwimmingSeadragon)
AucUtilFixAH, v8.2.6504 (SwimmingSeadragon)
BadBoy, vv1-classic
BadBoyCCleaner, vv8.2.0
BadBoyGuilded, vv8.2.0
BasicChatMods, vv4-classic
BeanCounter, v8.2.6505 (SwimmingSeadragon)
BetterVendorPrice, vv1.10.00
ClassicAutoDismount, v1.01
ClassicCastbars, vv1.2.1
ClassicCastbarsOptions, v
ClassicSpellActivations, v
ClassTrainerPlus, v0.5-beta
CTBarMod, v8.3.0.3
CTBuffMod, v8.3.0.3
CTCore, v8.3.0.1
CTLibrary, v8.3.0.3
CTMailMod, v8.3.0.1
CTMapMod, v8.3.0.3
CTPartyBuffs, v8.2.5.6
CTUnitFrames, v8.3.0.2
DidIDoIt, v1.2.0
EMAClassic, vv1.13.2-Release-v0.6(121022)
Enchantrix, v8.2.6506 (SwimmingSeadragon)
EnchantrixBarker, v8.2.6507 (SwimmingSeadragon)
ExtVendorUIClassic, v1.0.4
FloAspectBar, v
FloTotemBar, v
GatherMate2, v1.45.4
GlobalIgnoreList, v1.13.2
Grail, v107
GrailNPCsclassic, v27178
GrailNPCsclassicenUS, v27178
GrailQuestsclassic, v27178
GrailQuestsclassicenUS, v29297
GrailReputationsclassic, v007
GSE, v2.4.25
GSEGUI, v2.4.25
GSELDB, v2.4.25
Informant, v8.2.6508 (SwimmingSeadragon)
ISBoxer, v1.0
LetMeCast, v1.3
MageButtons, v1.0
Mapster, v1.8.5
Misspelled, v1.7.7
MonkeyBuddy, v
MonkeyLibrary, v
MonkeyQuest, v
MonkeyQuestLog, v
OmniCC, v8.2.4
QuestFrameFixer, v1.1.1
QuestIconDesaturation, v3.1
Questie, v5.5.1
QuestLogEx, v1.2
SlideBar, v8.2.6509 (SwimmingSeadragon)
SpamThrottleClassic, vv4.0c
Stubby, v8.2.6510 (SwimmingSeadragon)
TFTB, v1.10
TitanClassic, v1.1.5.11303
TitanClassicAmmo, v1.1.5.11303
TitanClassicBag, v1.1.5.11303
TitanClassicClock, v1.1.5.11303
TitanClassicGold, v1.1.5.11303
TitanClassicLocation, v1.1.5.11303
TitanClassicLootType, v1.1.5.11303
TitanClassicPerformance, v1.1.5.11303
TitanClassicRegen, v1.1.5.11303
TitanClassicRepair, v1.1.5.11303
TitanClassicVolume, v1.1.5.11303
TitanClassicXP, v1.1.5.11303
WhatsTraining, v1.8.7
Wholly, v077
BlizRuntimeLib_enUS v1.13.3.11303
(ck=96c)

I am editing it to a repeatable.

G[593]='SP K0461 L001 N255 A:2530 T:2530 P:B592+K10003912 E31727'

The next Grail has this corrected. There was a missing 0 from the K part of the P: code.