If this mod and Humanoid Alien Races are in the same list you get one of two errors:

If this is first you get:
Error in static constructor of AlienRace.HarmonyPatches: System.TypeInitializationException: The type initializer for 'AlienRace.HarmonyPatches' threw an exception. ---> System.Exception: Wrong null argument: brtrue NULL
at HarmonyLib.MethodBodyReader+<>c__DisplayClass24_0.<FinalizeILCodes>b__2 (HarmonyLib.CodeInstruction codeInstruction) [0x0015f] in <255414689d344b1385ae719f6cce8c55>:0
at HarmonyLib.CollectionExtensions.Do[T] (System.Collections.Generic.IEnumerable`1[T] sequence, System.Action`1[T] action) [0x00014] in <255414689d344b1385ae719f6cce8c55>:0
at HarmonyLib.MethodBodyReader.FinalizeILCodes (HarmonyLib.Emitter emitter, System.Collections.Generic.List`1[T] transpilers, System.Collections.Generic.List`1[T] endLabels, System.Boolean& hasReturnCode) [0x00203] in <255414689d344b1385ae719f6cce8c55>:0
at HarmonyLib.MethodCopier.Finalize (HarmonyLib.Emitter emitter, System.Collections.Generic.List`1[T] endLabels, System.Boolean& hasReturnCode) [0x00000] in <255414689d344b1385ae719f6cce8c55>:0
at HarmonyLib.MethodPatcher.CreateReplacement (System.Collections.Generic.Dictionary`2[System.Int32,HarmonyLib.CodeInstruction]& finalInstructions) [0x002be] in <255414689d344b1385ae719f6cce8c55>:0
at HarmonyLib.PatchFunctions.UpdateWrapper (System.Reflection.MethodBase original, HarmonyLib.PatchInfo patchInfo) [0x00057] in <255414689d344b1385ae719f6cce8c55>:0
at HarmonyLib.PatchProcessor.Patch () [0x000fc] in <255414689d344b1385ae719f6cce8c55>:0
at HarmonyLib.Harmony.Patch (System.Reflection.MethodBase original, HarmonyLib.HarmonyMethod prefix, HarmonyLib.HarmonyMethod postfix, HarmonyLib.HarmonyMethod transpiler, HarmonyLib.HarmonyMethod finalizer) [0x00028] in <255414689d344b1385ae719f6cce8c55>:0
at AlienRace.HarmonyPatches..cctor () [0x01d42] in <e718be9058284ff4888f04ae180d63dc>:0
--- End of inner exception stack trace ---
at (wrapper managed-to-native) System.Runtime.CompilerServices.RuntimeHelpers.RunClassConstructor(intptr)
at System.Runtime.CompilerServices.RuntimeHelpers.RunClassConstructor (System.RuntimeTypeHandle type) [0x0002a] in <eae584ce26bc40229c1b1aa476bfa589>:0
at Verse.StaticConstructorOnStartupUtility.CallAll () [0x00025] in <38562b1a2ab64eacb931fb5df05ca994>:0
UnityEngine.StackTraceUtility:ExtractStackTrace ()
Verse.Log:Error (string)
Verse.StaticConstructorOnStartupUtility:CallAll ()
Verse.PlayDataLoader/<>c:<DoPlayLoad>b__4_5 ()
Verse.LongEventHandler:ExecuteToExecuteWhenFinished ()
Verse.LongEventHandler:UpdateCurrentAsynchronousEvent ()
Verse.LongEventHandler:LongEventsUpdate (bool&)
(wrapper dynamic-method) Verse.Root:Verse.Root.Update_Patch1 (Verse.Root)
Verse.Root_Entry:Update ()
"

and if it's after you get:

"Error in static constructor of HermaphroditeGene.Main: System.TypeInitializationException: The type initializer for 'HermaphroditeGene.Main' threw an exception. ---> HarmonyLib.HarmonyException: Patching exception in method static Verse.AcceptanceReport RimWorld.PregnancyUtility::CanEverProduceChild(Verse.Pawn first, Verse.Pawn second) ---> System.Reflection.TargetInvocationException: Exception has been thrown by the target of an invocation. ---> System.ArgumentException: Label #3 is not marked in method `RimWorld.PregnancyUtility.CanEverProduceChild_Patch1'
at System.Reflection.Emit.ILGenerator.label_fixup (System.Reflection.MethodBase mb) [0x00053] in <eae584ce26bc40229c1b1aa476bfa589>:0
at System.Reflection.Emit.DynamicMethod.CreateDynMethod () [0x0004a] in <eae584ce26bc40229c1b1aa476bfa589>:0
at (wrapper managed-to-native) System.Reflection.MonoMethod.InternalInvoke(System.Reflection.MonoMethod,object,object[],System.Exception&)
at System.Reflection.MonoMethod.Invoke (System.Object obj, System.Reflection.BindingFlags invokeAttr, System.Reflection.Binder binder, System.Object[] parameters, System.Globalization.CultureInfo culture) [0x00032] in <eae584ce26bc40229c1b1aa476bfa589>:0
--- End of inner exception stack trace ---
at System.Reflection.MonoMethod.Invoke (System.Object obj, System.Reflection.BindingFlags invokeAttr, System.Reflection.Binder binder, System.Object[] parameters, System.Globalization.CultureInfo culture) [0x00048] in <eae584ce26bc40229c1b1aa476bfa589>:0
at System.Reflection.MethodBase.Invoke (System.Object obj, System.Object[] parameters) [0x00000] in <eae584ce26bc40229c1b1aa476bfa589>:0
at MonoMod.RuntimeDetour.Platforms.DetourRuntimeMonoPlatform.GetMethodHandle (System.Reflection.MethodBase method) [0x00011] in <255414689d344b1385ae719f6cce8c55>:0
at MonoMod.RuntimeDetour.Platforms.DetourRuntimeILPlatform.GetIdentifiable (System.Reflection.MethodBase method) [0x00000] in <255414689d344b1385ae719f6cce8c55>:0
at MonoMod.RuntimeDetour.Platforms.DetourRuntimeILPlatform.Pin (System.Reflection.MethodBase method) [0x00014] in <255414689d344b1385ae719f6cce8c55>:0
at MonoMod.RuntimeDetour.DetourHelper.Pin[T] (T method) [0x00005] in <255414689d344b1385ae719f6cce8c55>:0
at HarmonyLib.MethodPatcher.CreateReplacement (System.Collections.Generic.Dictionary`2[System.Int32,HarmonyLib.CodeInstruction]& finalInstructions) [0x00659] in <255414689d344b1385ae719f6cce8c55>:0
at HarmonyLib.PatchFunctions.UpdateWrapper (System.Reflection.MethodBase original, HarmonyLib.PatchInfo patchInfo) [0x00057] in <255414689d344b1385ae719f6cce8c55>:0
at HarmonyLib.PatchClassProcessor.ProcessPatchJob (HarmonyLib.PatchJobs`1+Job[T] job) [0x000bb] in <255414689d344b1385ae719f6cce8c55>:0
--- End of inner exception stack trace ---
at HarmonyLib.PatchClassProcessor.ReportException (System.Exception exception, System.Reflection.MethodBase original) [0x0010f] in <255414689d344b1385ae719f6cce8c55>:0
at HarmonyLib.PatchClassProcessor.Patch () [0x00093] in <255414689d344b1385ae719f6cce8c55>:0
at HarmonyLib.Harmony.<PatchAll>b__10_0 (System.Type type) [0x00007] in <255414689d344b1385ae719f6cce8c55>:0
at HarmonyLib.CollectionExtensions.Do[T] (System.Collections.Generic.IEnumerable`1[T] sequence, System.Action`1[T] action) [0x00014] in <255414689d344b1385ae719f6cce8c55>:0
at HarmonyLib.Harmony.PatchAll (System.Reflection.Assembly assembly) [0x00006] in <255414689d344b1385ae719f6cce8c55>:0
at HarmonyLib.Harmony.PatchAll () [0x0001b] in <255414689d344b1385ae719f6cce8c55>:0
at HermaphroditeGene.Main..cctor () [0x0000a] in <2702318819ab4f87a073f9ed7af7af84>:0
--- End of inner exception stack trace ---
at (wrapper managed-to-native) System.Runtime.CompilerServices.RuntimeHelpers.RunClassConstructor(intptr)
at System.Runtime.CompilerServices.RuntimeHelpers.RunClassConstructor (System.RuntimeTypeHandle type) [0x0002a] in <eae584ce26bc40229c1b1aa476bfa589>:0
at Verse.StaticConstructorOnStartupUtility.CallAll () [0x00025] in <38562b1a2ab64eacb931fb5df05ca994>:0
UnityEngine.StackTraceUtility:ExtractStackTrace ()
Verse.Log:Error (string)
Verse.StaticConstructorOnStartupUtility:CallAll ()
Verse.PlayDataLoader/<>c:<DoPlayLoad>b__4_5 ()
Verse.LongEventHandler:ExecuteToExecuteWhenFinished ()
Verse.LongEventHandler:UpdateCurrentAsynchronousEvent ()
Verse.LongEventHandler:LongEventsUpdate (bool&)
(wrapper dynamic-method) Verse.Root:Verse.Root.Update_Patch1 (Verse.Root)
Verse.Root_Entry:Update ()

"