The following error occurs when opening the mining or herbalism journal without knowing how to refine herbs or ore.

19x ...ceCraftSim/Modules/SimulationMode/Frames.lua:689: attempt to index field 'currentRecipeData' (a nil value)
[string "@CraftSim/Modules/SimulationMode/Frames.lua"]:689: in function UpdateVisibility' [string "@CraftSim/Main/CraftSim.lua"]:388: in function TriggerModulesByRecipeType'
[string "@CraftSim/Main/CraftSim.lua"]:111: in function TriggerModulesErrorSafe' [string "@CraftSim/Main/CraftSim.lua"]:134: in function <CraftSim/Main/CraftSim.lua:124> [string "=[C]"]: ? [string "=[C]"]: in function Init'
[string "@Blizzard_Professions/Blizzard_ProfessionsCrafting.lua"]:273: in function SelectRecipe' [string "@Blizzard_Professions/Blizzard_ProfessionsCrafting.lua"]:262: in function <...lizzard_Professions/Blizzard_ProfessionsCrafting.lua:253> [string "=[C]"]: ? [string "@SharedXML/CallbackRegistry.lua"]:143: in function <SharedXML/CallbackRegistry.lua:142> [string "=[C]"]: ? [string "@SharedXML/CallbackRegistry.lua"]:146: in function TriggerEvent'
...
[string "@SharedXML/Scroll/ScrollUtil.lua"]:322: in function SelectElementDataByPredicate' [string "@Blizzard_ProfessionsTemplates/Blizzard_ProfessionsRecipeList.lua"]:162: in function SelectRecipe'
[string "@Blizzard_Professions/Blizzard_ProfessionsCrafting.lua"]:692: in function Init' [string "@Blizzard_Professions/Blizzard_ProfessionsCrafting.lua"]:242: in function <...lizzard_Professions/Blizzard_ProfessionsCrafting.lua:241> [string "=[C]"]: ? [string "@SharedXML/CallbackRegistry.lua"]:143: in function <SharedXML/CallbackRegistry.lua:142> [string "=[C]"]: ? [string "@SharedXML/CallbackRegistry.lua"]:146: in function TriggerEvent'
[string "@Blizzard_Professions/Blizzard_ProfessionsFrame.lua"]:133: in function `SetProfessionInfo'
[string "@Blizzard_Professions/Blizzard_ProfessionsFrame.lua"]:88: in function <...s/Blizzard_Professions/Blizzard_ProfessionsFrame.lua:59>

Locals:
self =

{
UpdateVisibility = defined @CraftSim/Modules/SimulationMode/Frames.lua:676
Init = defined @CraftSim/Modules/SimulationMode/Frames.lua:13
CreateReagentOverwriteInput = defined @CraftSim/Modules/SimulationMode/Frames.lua:541
InitSpecModifier = defined @CraftSim/Modules/SimulationMode/Frames.lua:328
InitReagentOverwriteFrames = defined @CraftSim/Modules/SimulationMode/Frames.lua:625
GetSpecNodeModFramesByTabAndLayerAndLayerMax = defined @CraftSim/Modules/SimulationMode/Frames.lua:506
CreateReagentOverwriteFrame = defined @CraftSim/Modules/SimulationMode/Frames.lua:523
UpdateCraftingDetailsPanel = defined @CraftSim/Modules/SimulationMode/Frames.lua:727
InitOptionalReagentDropdowns = defined @CraftSim/Modules/SimulationMode/Frames.lua:549
}
specInfoFrame = CraftSimSpecInfoFrame {
BottomLeftCorner = Texture {
}
OnBackdropLoaded = defined @SharedXML/Backdrop.lua:152
GetBackdropColor = defined @SharedXML/Backdrop.lua:390
SetTransparency = defined @CraftSim/Util/Frames.lua:308
TopLeftCorner = Texture {
}
RightEdge = Texture {
}
decollapse = defined @CraftSim/Util/Frames.lua:245
ApplyBackdrop = defined @SharedXML/Backdrop.lua:294
SetBackdrop = defined @SharedXML/Backdrop.lua:329
ClearBackdrop = defined @SharedXML/Backdrop.lua:282
GetBackdropBorderColor = defined @SharedXML/Backdrop.lua:409
title = FontString {
}
collapsed = false
SetBorderBlendMode = defined @SharedXML/Backdrop.lua:266
PixelSnapDisabled = true
originalX = 290
hookFrame = Frame {
}
Center = Texture {
}
backdropInfo = {
}
OnBackdropSizeChanged = defined @SharedXML/Backdrop.lua:182
TopRightCorner = Texture {
}
content = Frame {
}
collapse = defined @CraftSim/Util/Frames.lua:233
scrollFrame = ScrollFrame {
}
originalY = 300
GetEdgeSize = defined @SharedXML/Backdrop.lua:188
BottomRightCorner = Texture {
}
0 =
TopEdge = Texture {
}
UpdateSize = defined @CraftSim/Util/Frames.lua:338
BottomEdge = Texture {
}
resetPosition = defined @CraftSim/Util/Frames.lua:287
SetupTextureCoordinates = defined @SharedXML/Backdrop.lua:214
HasBackdropInfo = defined @SharedXML/Backdrop.lua:278
SetBackdropBorderColor = defined @SharedXML/Backdrop.lua:422
collapseButton = Button {
}
SetupPieceVisuals = defined @SharedXML/Backdrop.lua:246
SetBackdropColor = defined @SharedXML/Backdrop.lua:399
LeftEdge = Texture {
}
GetBackdrop = defined @SharedXML/Backdrop.lua:347
}
hasOptionalReagents = false
(*temporary) = nil
(*temporary) = {
ShowWarning = defined @CraftSim/Util/Frames.lua:670
initDropdownMenu = defined @CraftSim/Util/Frames.lua:74
ToggleFrame = defined @CraftSim/Util/Frames.lua:66
InitTabSystem = defined @CraftSim/Util/Frames.lua:155
CreateCheckboxCustomCallback = defined @CraftSim/Util/Frames.lua:392
CreateTab = defined @CraftSim/Util/Frames.lua:208
CreateHelpIcon = defined @CraftSim/Util/Frames.lua:443
ShowError = defined @CraftSim/Util/Frames.lua:675
CreateCheckbox = defined @CraftSim/Util/Frames.lua:411
InitDebugFrame = defined @CraftSim/Util/Frames.lua:467
HandleAuctionatorOverlaps = defi

This seems to be because the addon will try to open simulation mode on an entry for which it is invalid, like the individual ore and herb entries. Clicking to a valid entry like refine herb or ore will fix the issue and prevent the lua from reappearing until the next UI reload or relog.