When my army succeeds in occupation, it will report an error. The army can't start cooling down and will never be able to use the army. It's too bad. The following is the error log.

System.NullReferenceException: Object reference not set to an instance of an object
at (wrapper dynamic-method) FactionColonies.SettlementFC.FactionColonies.SettlementFC.processMilitaryEvent_Patch0(FactionColonies.SettlementFC)
at (wrapper dynamic-method) FactionColonies.FCEventMaker.FactionColonies.FCEventMaker.ProcessEvents_Patch0(System.Collections.Generic.List`1<FactionColonies.FCEvent>&)
at FactionColonies.FactionFC.WorldComponentTick () [0x000c5] in <6051c84f93ba4c4dbcbe9c5875777499>:0
at RimWorld.Planet.WorldComponentUtility.WorldComponentTick (RimWorld.Planet.World world) [0x00013] in <e13bd2f1929544099ed2b58e66ece833>:0
UnityEngine.StackTraceUtility:ExtractStackTrace ()
(wrapper dynamic-method) Verse.Log:Verse.Log.Error_Patch1 (string)
RimWorld.Planet.WorldComponentUtility:WorldComponentTick (RimWorld.Planet.World)
RimWorld.Planet.World:WorldTick ()
(wrapper dynamic-method) Verse.TickManager:Verse.TickManager.DoSingleTick_Patch1 (Verse.TickManager)
Verse.TickManager:TickManagerUpdate ()
(wrapper dynamic-method) Verse.Game:Verse.Game.UpdatePlay_Patch1 (Verse.Game)
Verse.Root_Play:Update ()