With the command line or while using Bagnon.

1x SortBags/SortBags.lua:22: attempt to call field 'GetBankBagSlotFlag' (a nil value)
[string "@SortBags/SortBags.lua"]:22: in function SortBankBags' [string "SortBankBags()"]:1: in main chunk [string "=[C]"]: in function RunScript'
[string "@FrameXML/ChatFrame.lua"]:2201: in function ?' [string "@FrameXML/ChatFrame.lua"]:4938: in function <FrameXML/ChatFrame.lua:4884> [string "=[C]"]: in function ChatEdit_ParseText'
[string "@FrameXML/ChatFrame.lua"]:4601: in function <FrameXML/ChatFrame.lua:4600>
[string "=[C]"]: in function ChatEdit_SendText' [string "@FrameXML/ChatFrame.lua"]:4637: in function ChatEdit_OnEnterPressed'
[string "*ChatFrame.xml:121_OnEnterPressed"]:1: in function <[string "*ChatFrame.xml:121_OnEnterPressed"]:1>

Locals:
(for index) = 8
(for limit) = 1
(for step) = -1
i = 8
(*temporary) = nil
(*temporary) = 7
(*temporary) = 1
(*temporary) = "attempt to call field 'GetBankBagSlotFlag' (a nil value)"
_G =

{
ContainerFrame5Item7 = ContainerFrame5Item7 {
}
DH_HAVOC_CORE_ABILITY_2 = "Strong melee attack that consumes Fury. If it critical strikes, some Fury is refunded."
BT4Button85Shine14 = BT4Button85Shine14 {
}
GetTrainerServiceTypeFilter = defined =[C]:-1
UNIT_NAMES_COMBATLOG_TOOLTIP = "Color unit names."
ScrapTooltipTextLeft1 = ScrapTooltipTextLeft1 {
}
LE_GAME_ERR_CHAT_RAID_RESTRICTED_TRIAL = 790
SPELL_FAILED_CUSTOM_ERROR_71 = "This partygoer wants to dance with you."
LE_GAME_ERR_PET_SPELL_TARGETS_DEAD = 408
BT4Button58 = BT4Button58 {
}
CompactUnitFrameProfilesGeneralOptionsFrameHealthTextDropdownButtonNormalTexture = CompactUnitFrameProfilesGeneralOptionsFrameHealthTextDropdownButtonNormalTexture {
}
PawnItemComparer = defined @Pawn/Pawn.lua:4028
MultiBarLeftButton7 = MultiBarLeftButton7 {
}
AudioOptionsVoicePanelOutputDeviceDropdownButtonHighlightTexture = AudioOptionsVoicePanelOutputDeviceDropdownButtonHighlightTexture {
}
LE_GAME_ERR_INVALID_FOLLOW_PVP_COMBAT = 361
MerchantItem4AltCurrencyFrameItem1Text = MerchantItem4AltCurrencyFrameItem1Text {
}
BINDING_NAME_NAMEPLATES = "Show Enemy Name Plates"
CHAT_HEADER_SUFFIX = ": "
EncounterDetails_SpellAurasScrollScrollChildFrame = EncounterDetails_SpellAurasScrollScrollChildFrame {
}
MultiBarBottomRightButton8Shine5 = MultiBarBottomRightButton8Shine5 {
}
IsReferAFriendLinked = defined =[C]:-1
UnitFrameManaBar_UnregisterDefaultEvents = defined @FrameXML/UnitFrame.lua:623
WhatsTrainingFrameRow3Spell = WhatsTrainingFrameRow3Spell {
}
CALENDAR_RAID_RESET_DESCRIPTION = "%1$s resets at %2$s."
CraftExpandTabLeft = CraftExpandTabLeft {
}
MoneyFrame_OnEvent = defined @FrameXML/MoneyFrame.lua:224
WatchFrameItem_OnEvent = defined @Interface_Wrath/FrameXML/WatchFrame.lua:1176
CompactRaidFrameManagerDisplayFrameHiddenModeToggleTopRight =
CompactRaidFrameManagerDisplayFrameHiddenModeToggleTopRight {
}
LE_GAME_ERR_ONLY_ONE_QUIVER = 33
GetMonitorAspectRatio = defined =[C]:-1
PallyPowerBlessingsFramePlayer12Line5 = PallyPowerBlessingsFramePlayer12Line5 {
}
LOSS_OF_CONTROL_DISPLAY_FEAR = "Feared"
Graphics_QualityText = Graphics_QualityText {
}
OverrideActionBarButton6Shine11 = OverrideActionBarButton6Shine11 {
}
LibDBIcon10_BugSack = LibDBIcon10_BugSack {
}
CompactUnitFrameProfilesSaveButton = CompactUnitFrameProfilesSaveButton {
AUCTIONATOR_L_DEFAULT_LIST_HEADER = "Default Shopping List"
ACTION_SPELL_MISSED_POSSESSIVE = "1"
PetPaperDollFrameTab3Right = PetPaperDollFrameTab3Right {
}
Is64BitClient = defined =[C]:-1
TELLMEWHEN_VERSION_FULL = "10.0.8 "
TitanPanelVolumeControlFrameDialogTitle = TitanPanelVolumeControlFrameDialogTitle {
}
CompactRaidFrameManagerDisplayFrameFilterOptionsFilterRoleTankMiddleMiddle = CompactRaidFrameManagerDisplayFrameFilterOptionsFilterRoleTankMiddleMiddle {
}
SortQuestWatches = defined =[C]:-1
ContainerFrame4Item16Cooldown = ContainerFrame4Item16Cooldown {
}
DUNGEON_FLOOR_DRAGONBLIGHTCHROMIESCENARIO2 = "Andorhal"
AudioOptionsVoicePanel_OnShow = defined @FrameXML/AudioOptionsPanels.lua:311
WowTokenRedemptionFrameBg = WowTokenRedemptionFrameBg {
}
TitanPanelRestPlusButton_CheckCapOrange = defined @TitanClassicRestPlus/TitanClassicRestPlus.lua:1966
LAG_TOLERANCE = "Lag Tolerance"
RCLootCouncil_Tooltip_ParseTextLeft1 = RCLootCouncil_Tooltip_ParseTextLeft1 {
}
TitanPanelBartender4ButtonRightClickMenuPushedTexture = TitanPanelBartender4ButtonRightClickMenuPushedTexture {
}
SendStationeryBackgroundRight = SendStationeryBackgroundRight {
}
_ = "Container"
AUCTIONATOR_L_HIDE = "Hide"
MultiBarLeftButton9Border = MultiBarLeftButton9Border {
}
LE_GAME_ERR_NOT_ON_TOURNAMENT_REALM = 886
UIWidgetCenterDisplayFrameText

To Set Flag
use C_Container.SetBagSlotFlag(newIndex, LE_BAG_FILTER_FLAG_IGNORE_CLEANUP, value)
where newIndex for bank bags is (5, 6, 7, 8, 9, 10, 11) and value is 'true' to disable sorting that bag or 'false' to enable sorting that bag. Reminder: you cannot set the sorting flag for the main bank bag.

To Read Flag
use C_Container.GetBagSlotFlag(newIndex, LE_BAG_FILTER_FLAG_IGNORE_CLEANUP)