The outfitter bar was missing, so I tried to turn it off and back on from the addon settings (uncheck and check the box). And got the below error:

Edit
This is with the latest version from Curse, which reports it as 1.2.7, not sure why the addons list below still shows it at 1.2.0
Edit

Date: 2020-07-03 16:05:30
ID: 3
Error occured in: Global
Count: 6
Message: ..\AddOns\Outfitter\OutfitterBar.lua line 219:
attempt to index field 'Settings' (a nil value)
Debug:
(tail call): ?
[C]: ?
Outfitter\OutfitterBar.lua:219: SetShowOutfitBar()
[string ":OnClick"]:2:
[string ":OnClick"]:1
Locals:
(*temporary) = "LeftButton"
(*temporary) = false
(*temporary) = defined =[C]:-1

AddOns:
Swatter, v8.2.6377 (SwimmingSeadragon)
ActionBarSaver, v
AddOnSkins, v4.40
AdiBags, vv1.9.20-classic
AdiBagsOutfitter, vv1.5.5-classic
AdvancedInterfaceOptions, v1.3.4
AskMrRobotClassic, v2
AtlasLootClassic, vv1.5.1
AtlasLootClassicData, vv1.5.1
AtlasLootClassicDungeonsAndRaids, vv1.5.1
AtlasLootClassicMaps, vv1.0.0
AucAdvanced, v8.2.6430 (SwimmingSeadragon)
AucFilterBasic, v8.2.6364 (SwimmingSeadragon)
AucScanData, v8.2.6365 (SwimmingSeadragon)
AucStatHistogram, v8.2.6366 (SwimmingSeadragon)
AucStatiLevel, v8.2.6370 (SwimmingSeadragon)
AucStatPurchased, v8.2.6367 (SwimmingSeadragon)
AucStatSimple, v8.2.6399 (SwimmingSeadragon)
AucStatStdDev, v8.2.6369 (SwimmingSeadragon)
AucUtilFixAH, v8.2.6371 (SwimmingSeadragon)
AutoAmmo, v1.1.3
AutoCombatLogger, v8.3.2
AVQ, v28
BadBoy, vv1-classic
BattlegroundTargets, v11304-4
BattleInfo, v@project-version
BCT, v1.35
BeanCounter, v8.2.6434 (SwimmingSeadragon)
BestInSlotClassic, v2.5.2
BetterVendorPrice, vv1.13.04
ClassicLootAssistant, v
DBMCore, v1.13.51
DBMDefaultSkin, v
DBMPvP, vr91
DBMStatusBarTimers, v
Details, v
DetailsStreamer, v
DetailsTinyThreat, v
Dismounter, v1.2.1
ElvUI, v1.24
ElvUIBenikUIClassic, v1.12
ElvUIDTBars2, v1.0
ElvUIExtraDataTextsClassic, v1.0.2
ElvUILocationPlus, v1.03
ElvUINutsAndBoltsClassic, v1.02
ElvUIPVPDT, v1.00
ElvUIQuestXPClassic, v1.0.0
Enchantrix, v8.2.6428 (SwimmingSeadragon)
FarmHud, v8.3-6-classic-release
FarmLog, vv1.19
FishingBuddy, v0.7.3 Beta 5
GatherMate2, v1.45.5
GeartoGearPlanner, vv1.3.7
GigaAutoResourcesTracker, v1.1.0
Hemlock, v1.1.2
HHTD, v2.4.9.5
honorspy, v1.7.3
HPH, v2.13
Immersion, v1.2.3
InFlightLoad, v1.13.005
Informant, v8.2.6374 (SwimmingSeadragon)
LFGMatchMaker, v1.0.8
MikScrollingBattleText, v5.7.149
Molinari, v80300.66-Release
NovaWorldBuffs, v1.66
Outfitter, v1.2.0
Plater, vPlater-1.13.4.81-Classic
ProjectAzilroka, v1.67
QuestAnnounce, v8.0.2.1
Questie, v6.0.0
RangeDisplay, vv4.9.1
RareAware, v1.0
RCLootCouncilClassic, v0.10.1
RecipeRadarClassic, v1.0.0.23
RollTrackerClassic, v2.21
Routes, vv1.6.3
SkullMe, v3.0.4
SlideBar, v8.2.6375 (SwimmingSeadragon)
SpeedyMount, v1.1.2
Spy, v1.1.0
Stubby, v8.2.6376 (SwimmingSeadragon)
TomTom, vv11304-1.1.2
totalRP3, v1.6.13
totalRP3Data, v
WeakAuras, v2.17.8
WeakAurasCompanion, v1.1.0
WeaponSwingTimer, v4.1.0
WIM, v3.8.11
WoWPro, v1.13.4-B2
WoWProAchievements, v1.13.2I
WoWProDailies, v1.13.2I
WoWProLeveling, v1.13.4-B2
WoWProWorldEvents, v1.13.2I
XLoot, v8.1-1
XLootFrame, v8.1-1
XLootGroup, v8.1-1
XLootMaster, v8.1-1
XLootMonitor, v8.1-1
BlizRuntimeLib_enUS v1.13.4.11304
(ck=ac1)

I also got an error from AddonSkins, from ElvUI, with Outfitter, so I turned that seting off in ElvUI. And did a /reloadui, and got the below error:

Date: 2020-07-03 16:13:25
ID: 1
Error occured in: Global
Count: 1
Message: ..\AddOns\Outfitter\OutfitterOutfits.lua line 252:
attempt to index local 'vItem' (a string value)
Debug:
(tail call): ?
[C]: ?
Outfitter\OutfitterOutfits.lua:252: CheckOutfit()
Outfitter\Outfitter.lua:6227: CheckDatabase()
Outfitter\Outfitter.lua:4705: Function()
...fitter\Libraries/MC2SchedulerLib/MC2SchedulerLib.lua:242: OnUpdate2()
...fitter\Libraries/MC2SchedulerLib/MC2SchedulerLib.lua:178: OnUpdate()
...fitter\Libraries/MC2SchedulerLib/MC2SchedulerLib.lua:20:
...fitter\Libraries/MC2SchedulerLib/MC2SchedulerLib.lua:20
Locals:
(*temporary) = 9.945001
(*temporary) = defined =[C]:-1

AddOns:
Swatter, v8.2.6377 (SwimmingSeadragon)
ActionBarSaver, v
AddOnSkins, v4.40
AdiBags, vv1.9.20-classic
AdiBagsOutfitter, vv1.5.5-classic
AdvancedInterfaceOptions, v1.3.4
AskMrRobotClassic, v2
AtlasLootClassic, vv1.5.1
AtlasLootClassicData, vv1.5.1
AtlasLootClassicDungeonsAndRaids, vv1.5.1
AtlasLootClassicMaps, vv1.0.0
AucAdvanced, v8.2.6430 (SwimmingSeadragon)
AucFilterBasic, v8.2.6364 (SwimmingSeadragon)
AucScanData, v8.2.6365 (SwimmingSeadragon)
AucStatHistogram, v8.2.6366 (SwimmingSeadragon)
AucStatiLevel, v8.2.6370 (SwimmingSeadragon)
AucStatPurchased, v8.2.6367 (SwimmingSeadragon)
AucStatSimple, v8.2.6399 (SwimmingSeadragon)
AucStatStdDev, v8.2.6369 (SwimmingSeadragon)
AucUtilFixAH, v8.2.6371 (SwimmingSeadragon)
AutoAmmo, v1.1.3
AutoCombatLogger, v8.3.2
AVQ, v28
BadBoy, vv1-classic
BattlegroundTargets, v11304-4
BattleInfo, v@project-version
BCT, v1.35
BeanCounter, v8.2.6434 (SwimmingSeadragon)
BestInSlotClassic, v2.5.2
BetterVendorPrice, vv1.13.04
ClassicLootAssistant, v
DBMCore, v1.13.51
DBMDefaultSkin, v
DBMStatusBarTimers, v
Details, v
DetailsStreamer, v
DetailsTinyThreat, v
Dismounter, v1.2.1
ElvUI, v1.24
ElvUIBenikUIClassic, v1.12
ElvUIDTBars2, v1.0
ElvUIExtraDataTextsClassic, v1.0.2
ElvUILocationPlus, v1.03
ElvUINutsAndBoltsClassic, v1.02
ElvUIPVPDT, v1.00
ElvUIQuestXPClassic, v1.0.0
Enchantrix, v8.2.6428 (SwimmingSeadragon)
FarmHud, v8.3-6-classic-release
FarmLog, vv1.19
FishingBuddy, v0.7.3 Beta 5
GatherMate2, v1.45.5
GeartoGearPlanner, vv1.3.7
GigaAutoResourcesTracker, v1.1.0
Hemlock, v1.1.2
HHTD, v2.4.9.5
honorspy, v1.7.3
HPH, v2.13
Immersion, v1.2.3
InFlightLoad, v1.13.005
Informant, v8.2.6374 (SwimmingSeadragon)
LFGMatchMaker, v1.0.8
MikScrollingBattleText, v5.7.149
Molinari, v80300.66-Release
NovaWorldBuffs, v1.66
Outfitter, v1.2.0
Plater, vPlater-1.13.4.81-Classic
ProjectAzilroka, v1.67
QuestAnnounce, v8.0.2.1
Questie, v6.0.0
RangeDisplay, vv4.9.1
RareAware, v1.0
RCLootCouncilClassic, v0.10.1
RecipeRadarClassic, v1.0.0.23
RollTrackerClassic, v2.21
Routes, vv1.6.3
SkullMe, v3.0.4
SlideBar, v8.2.6375 (SwimmingSeadragon)
SpeedyMount, v1.1.2
Spy, v1.1.0
Stubby, v8.2.6376 (SwimmingSeadragon)
TomTom, vv11304-1.1.2
totalRP3, v1.6.13
totalRP3Data, v
WeakAuras, v2.17.8
WeakAurasCompanion, v1.1.0
WeaponSwingTimer, v4.1.0
WIM, v3.8.11
WoWPro, v1.13.4-B2
WoWProAchievements, v1.13.2I
WoWProDailies, v1.13.2I
WoWProLeveling, v1.13.4-B2
WoWProWorldEvents, v1.13.2I
XLoot, v8.1-1
XLootFrame, v8.1-1
XLootGroup, v8.1-1
XLootMaster, v8.1-1
XLootMonitor, v8.1-1
BlizRuntimeLib_enUS v1.13.4.11304
(ck=ab2)

I reverted the ammo fix, that was causing your issue. Also fixed version reported in game.