Exception filling window for RimWorld.MainTabWindow_Menu: System.ArgumentNullException: Value cannot be null.
Parameter name: key
[Ref 367F151F]
[0x00006] in <51fded79cd284d4d911c5949aff4cb21>:0
at System.Collections.Generic.Dictionary`2[TKey,TValue].FindEntry (TKey key) [0x00008] in <51fded79cd284d4d911c5949aff4cb21>:0
at System.Collections.Generic.Dictionary`2[TKey,TValue].get_Item (TKey key) [0x00000] in <51fded79cd284d4d911c5949aff4cb21>:0
at PeteTimesSix.ResearchReinvented_SteppingStones.Patches.MainTabWindow_Research_OffsetHack_X.ResearchViewX (System.Single& __result, Verse.ResearchProjectDef __instance) [0x0000f] in <905c30c9bb6543d6b5880d98e531ac87>:0
at Verse.ResearchProjectDef.get_ResearchViewX () [0x0000d] in <981a33edf24d499488b0f820d94638e1>:0
- POSTFIX PeteTimesSix.ResearchReinvented_SteppingStones: Void PeteTimesSix.ResearchReinvented_SteppingStones.Patches.MainTabWindow_Research_OffsetHack_X:ResearchViewX(Single& __result, ResearchProjectDef __instance)
at RimWorld.MainTabWindow_Research.PosX (Verse.ResearchProjectDef d) [0x00000] in <981a33edf24d499488b0f820d94638e1>:0
at RimWorld.MainTabWindow_Research.ViewSize (RimWorld.ResearchTabDef tab) [0x0007f] in <981a33edf24d499488b0f820d94638e1>:0
at RimWorld.MainTabWindow_Research.set_CurTab (RimWorld.ResearchTabDef value) [0x00018] in <981a33edf24d499488b0f820d94638e1>:0
at FluffyResearchTree.MainTabsRoot_ToggleTab.Postfix () [0x00016] in <ac8f827eb926440a9eab532f5e7c75d9>:0
at RimWorld.MainTabsRoot.ToggleTab (RimWorld.MainButtonDef newTab, System.Boolean playSound) [0x0010f] in <981a33edf24d499488b0f820d94638e1>:0
- PREFIX Fluffy.ResearchTree: Void FluffyResearchTree.MainTabsRoot_ToggleTab:Prefix(MainButtonDef& newTab)
- PREFIX Dubwise.DubsMintMenus: Void DubsMintMenus.HarmonyPatches+Patch_MainTabsRoot:Prefix(MainButtonDef& newTab)
- POSTFIX Fluffy.ResearchTree: Void FluffyResearchTree.MainTabsRoot_ToggleTab:Postfix()
- POSTFIX Troy_Alias.TacticalGroups: Void TacticalGroups.HarmonyPatches:EntriesDirty()
at RimWorld.MainTabsRoot.SetCurrentTab (RimWorld.MainButtonDef tab, System.Boolean playSound) [0x0000a] in <981a33edf24d499488b0f820d94638e1>:0
at RimWorld.MainTabsRoot.EscapeCurrentTab (System.Boolean playSound) [0x00000] in <981a33edf24d499488b0f820d94638e1>:0
at RimWorld.MainMenuDrawer.CloseMainTab () [0x0000d] in <981a33edf24d499488b0f820d94638e1>:0
at RimWorld.MainMenuDrawer+<>c.<DoMainMenuControls>b__24_3 () [0x00000] in <981a33edf24d499488b0f820d94638e1>:0
at Verse.ListableOption.DrawOption (UnityEngine.Vector2 pos, System.Single width) [0x00049] in <981a33edf24d499488b0f820d94638e1>:0
at Verse.OptionListingUtility.DrawOptionListing (UnityEngine.Rect rect, System.Collections.Generic.List`1[T] optList) [0x00099] in <981a33edf24d499488b0f820d94638e1>:0
- PREFIX Lauriichan.PriorityMaster: Void PriorityMod.PatchesV6.RestartPatches:OptionListingUtilPrefix(Rect rect, List`1 optList)
- PREFIX rimworld.aRandomKiwi.RimTheme: Boolean aRandomKiwi.RimThemes.DrawOptionListing_Patch:Prefix(Single& __result)
- PREFIX rimworld.randomKiwi.FFM: Boolean aRandomKiwi.ARS.OptionListingUtility_Patch:Listener(Rect rect, List`1 optList)
at RimWorld.MainMenuDrawer.DoMainMenuControls (UnityEngine.Rect rect, System.Boolean anyMapFiles) [0x00591] in <981a33edf24d499488b0f820d94638e1>:0
- TRANSPILER UnlimitedHugs.HugsLib: IEnumerable`1 HugsLib.Patches.MainMenuDrawer_Quickstart_Patch:QuicktestButtonUsesQuickstarter(IEnumerable`1 instructions)
- PREFIX Lauriichan.PriorityMaster: Void PriorityMod.PatchesV6.RestartPatches:MainControlsPrefix(Rect& rect)
- POSTFIX Lauriichan.PriorityMaster: Void PriorityMod.PatchesV6.RestartPatches:MainControlsPostfix(Rect& rect)
- POSTFIX rimworld.aRandomKiwi.RimTheme: Void aRandomKiwi.RimThemes.DoMainMenuControls_Patch:Postfix(Rect rect, Boolean anyMapFiles)
at RimWorld.MainTabWindow_Menu.DoWindowContents (UnityEngine.Rect rect) [0x00000] in <981a33edf24d499488b0f820d94638e1>:0
at Verse.Window.InnerWindowOnGUI (System.Int32 x) [0x001a6] in <981a33edf24d499488b0f820d94638e1>:0
UnityEngine.StackTraceUtility:ExtractStackTrace ()
(wrapper dynamic-method) MonoMod.Utils.DynamicMethodDefinition:Verse.Log.Error_Patch3 (string)
Verse.Window:InnerWindowOnGUI (int)
UnityEngine.GUI:CallWindowDelegate (UnityEngine.GUI/WindowFunction,int,int,UnityEngine.GUISkin,int,single,single,UnityEngine.GUIStyle)

when first time open tab research , in modlist i have research tree (continued) and stepping stones.