Got the following error with 7.3.

ID: 1
Error occured in: Global
Count: 1
Message: ...\PetTracker\Libs\Sushi-3.0\Classes\DropdownFrame.lua line 124:
Usage: PlaySound(soundKitID, optional["SFX","Music","Ambience", "Dialog" or "Master"], [forceNoDuplicates, runFinishCallback])
Debug:
[C]: PlaySound()
...\PetTracker\Libs\Sushi-3.0\Classes\DropdownFrame.lua:124: Toggle()
PetTracker\Features\WorldMap.lua:238:
PetTracker\Features\WorldMap.lua:237
Locals:
(*temporary) = "igMainMenuOptionCheckBoxOn"

AddOns:
Swatter, v7.4.5714 (TasmanianThylacine)
AlreadyKnown, v1.14
AucAdvanced, v7.4.5714 (TasmanianThylacine)
AucFilterBasic, v7.4.5714 (TasmanianThylacine)
AucFilterOutlier, v7.4.5714.5459(7.4/embedded)
AucMatchUndercut, v7.4.5714.5585(7.4/embedded)
AucScanData, v7.4.5714 (TasmanianThylacine)
AucStatHistogram, v7.4.5714 (TasmanianThylacine)
AucStatiLevel, v7.4.5714 (TasmanianThylacine)
AucStatPurchased, v7.4.5714 (TasmanianThylacine)
AucStatSales, v7.4.5714.5598(7.4/embedded)
AucStatSimple, v7.4.5714 (TasmanianThylacine)
AucStatStdDev, v7.4.5714 (TasmanianThylacine)
AucStatWOWEcon, v7.4.5714.5613(7.4/embedded)
AucUtilAHWindowControl, v7.4.5714.5575(7.4/embedded)
AucUtilAppraiser, v7.4.5714.5704(7.4/embedded)
AucUtilAskPrice, v7.4.5714.5599(7.4/embedded)
AucUtilAutoMagic, v7.4.5714.5686(7.4/embedded)
AucUtilCompactUI, v7.4.5714.5694(7.4/embedded)
AucUtilEasyBuyout, v7.4.5714.5576(7.4/embedded)
AucUtilFixAH, v7.4.5714 (TasmanianThylacine)
AucUtilItemSuggest, v7.4.5714.5651(7.4/embedded)
AucUtilPriceLevel, v7.4.5714.5633(7.4/embedded)
AucUtilScanButton, v7.4.5714.5631(7.4/embedded)
AucUtilScanFinish, v7.4.5714.5588(7.4/embedded)
AucUtilScanProgress, v7.4.5714.4979(7.4/embedded)
AucUtilScanStart, v7.4.5714.5347(7.4/embedded)
AucUtilSearchUI, v7.4.5714.5710(7.4/embedded)
AucUtilSimpleAuction, v7.4.5714.5705(7.4/embedded)
AucUtilVendMarkup, v7.4.5714.4828(7.4/embedded)
Auctionator, v4.0.19
Babylonian, v5.1.DEV.332(/embedded)
BadPet, vv1.0.9
BartrubySummonPet, v1.26
BattlePetBreedID, vr154
BeanCounter, v7.4.5714 (TasmanianThylacine)
BulkMail2Inbox, v7.0.0
BuyEmAll, v3.4.3
ClassHallButtonGarrison, v
Configator, v5.1.DEV.406(/embedded)
DebugLib, v5.1.DEV.337(/embedded)
DropTheCheapestThing, vv70100
Enchantrix, v7.4.5714 (TasmanianThylacine)
EnchantrixBarker, v7.4.5714 (TasmanianThylacine)
GatherMate2, v1.41
HandyNotes, vv1.4.15
HandyNotesDungeonLocations, v1.21
HandyNotesLegionTownPortals, v0.0.1
HandyNotesSuramarTelemancy, v1
HandyNotesWorldMapButton, v2.6
Informant, v7.4.5714 (TasmanianThylacine)
iSoldMore, v
kSellGreyNRepair, v1.2
LibExtraTip, v5.12.DEV.423(/embedded)
MinersCoffeeAndPick, v1.9
OPie, vVanilla 1
PetTracker, v7.1.4
PetTrackerBreeds, v7.1.4
PetTrackerBroker, v
PetTrackerConfig, v7.1.4
PetTrackerJournal, v7.1.4
PetTrackerSwitcher, v7.1.4
PetTrackerUpgrades, v7.1.4
PremadeGroupsFilter, v1.14
Rematch, v4.7.5
SlideBar, v7.4.5714 (TasmanianThylacine)
Stubby, v7.4.5714 (TasmanianThylacine)
SushiSort, v7.0.0.0
TheUndermineJournal, v4.7.20170829
TipHelper, v5.12.DEV.405(/embedded)
Titan, v5.12.3.70300
TitanBag, v5.12.3.70300
TitanClock, v5.12.3.70300
TitanCurrenciesMulti, v5.26
TitanGold, v5.12.3.70300
TitanLootType, v5.12.3.70300
TitanPerformance, v5.12.3.70300
TitanRepair, v5.12.3.70300
TitanVolume, v5.12.3.70300
TitanXP, v5.12.3.70300
TomTom, vv70200-1.0.0
WorldQuestGroupFinder, v0.27
WorldQuestsList, v42
BlizRuntimeLib_enUS v7.3.0.70300
(ck=bf6)

I have not yet tried this but it appears that the PetTracker mod has an outdated Sushi library in it. My Sushi files are dated 5/11/17 but the newest Sushi library is dated 9/1/17. I am going to update my library files manually and see if that solves this issue. The URL for new library is: http://jaliborc.github.io/Sushi-3.0/