Exception from asynchronous event: System.Reflection.TargetInvocationException: Exception has been thrown by the target of an invocation. ---> System.ArgumentException: An element with the same key already exists in the dictionary.
  at System.Collections.Generic.Dictionary`2[Verse.ThingDef,System.Single].Add (Verse.ThingDef key, Single value) [0x00171] in /Users/builduser/buildslave/mono/build/mcs/class/corlib/System.Collections.Generic/Dictionary.cs:432
  at RimWorld.BiomeDef.CommonalityOfPlant (Verse.ThingDef plantDef) [0x000b4] in C:\Dev\RimWorld\Assets\Scripts\RimWorld\Defs\DefTypes\BiomeDef.cs:247
  at RimWorld.BiomeDef+<>c__Iterator87.MoveNext () [0x00058] in C:\Dev\RimWorld\Assets\Scripts\RimWorld\Defs\DefTypes\BiomeDef.cs:179
  at System.Linq.Enumerable+<CreateWhereIterator>c__Iterator1D`1[Verse.ThingDef].MoveNext () [0x00000] in <filename unknown>:0
  at System.Linq.Enumerable.ToDictionary[ThingDef,ThingDef,Boolean] (IEnumerable`1 source, System.Func`2 keySelector, System.Func`2 elementSelector, IEqualityComparer`1 comparer) [0x00000] in <filename unknown>:0
  at System.Linq.Enumerable.ToDictionary[ThingDef,ThingDef,Boolean] (IEnumerable`1 source, System.Func`2 keySelector, System.Func`2 elementSelector) [0x00000] in <filename unknown>:0
  at FluffyManager.ManagerJob_Forestry..ctor (FluffyManager.Manager manager) [0x00000] in <filename unknown>:0
  at FluffyManager.ManagerTab_Forestry..ctor (FluffyManager.Manager manager) [0x00000] in <filename unknown>:0
  at FluffyManager.Manager..ctor (Verse.Map map) [0x00000] in <filename unknown>:0
  at (wrapper managed-to-native) System.Reflection.MonoCMethod:InternalInvoke (object,object[],System.Exception&)
  at System.Reflection.MonoCMethod.Invoke (System.Object obj, BindingFlags invokeAttr, System.Reflection.Binder binder, System.Object[] parameters, System.Globalization.CultureInfo culture) [0x00119] in /Users/builduser/buildslave/mono/build/mcs/class/corlib/System.Reflection/MonoMethod.cs:513
  --- End of inner exception stack trace ---