Hey guys. We investigated this issue today and found that it seems to be caused by the mod HugsLib. The related error message is
Exception filling window for RimWorld.Dialog_Options: System.NullReferenceException: Object reference not set to an instance of an object
at (wrapper dynamic-method) RimWorld.Dialog_Options.RimWorld.Dialog_Options.DoModOptions_Patch0(RimWorld.Dialog_Options,Verse.Listing_Standard)
at RimWorld.Dialog_Options.DoOptions (Verse.OptionCategoryDef category, UnityEngine.Rect inRect) [0x0015e] in D:\dev\unity\rimworld\Assets\Scripts\RimWorld\UI\Dialogs\Dialog_Options.cs:189
at RimWorld.Dialog_Options.DoWindowContents (UnityEngine.Rect inRect) [0x00109] in D:\dev\unity\rimworld\Assets\Scripts\RimWorld\UI\Dialogs\Dialog_Options.cs:123
at Verse.Window.InnerWindowOnGUI (System.Int32 x) [0x0023e] in D:\dev\unity\rimworld\Assets\Scripts\Verse\UI\Windows\Window.cs:247
UnityEngine.Debug:LogError (object)
Verse.Log:Error (string) (at Assets/Scripts/LudeonTK/Utility/Log/Log.cs:115)
Verse.Window:InnerWindowOnGUI (int) (at Assets/Scripts/Verse/UI/Windows/Window.cs:251)
UnityEngine.GUI:CallWindowDelegate (UnityEngine.GUI/WindowFunction,int,int,UnityEngine.GUISkin,int,single,single,UnityEngine.GUIStyle)