i have same issue with raids...

Check the dev log.
System.NullReferenceException: Object reference not set to an instance of an object
at MoreFactionInteraction.World_Incidents.IncidentWorker_BumperCrop+<>c__DisplayClass7_0.<RandomNearbyGrowerSettlement>b__0 (RimWorld.Planet.Settlement settlement) [0x00000] in <filename unknown>:0
at System.Linq.Enumerable+<CreateWhereIterator>c__Iterator1D`1[RimWorld.Planet.Settlement].MoveNext () [0x00000] in <filename unknown>:0
at System.Collections.Generic.List`1[RimWorld.Planet.Settlement].AddEnumerable (IEnumerable`1 enumerable) [0x00000] in <filename unknown>:0
at System.Collections.Generic.List`1[RimWorld.Planet.Settlement]..ctor (IEnumerable`1 collection) [0x00000] in <filename unknown>:0
at System.Linq.Enumerable.ToList[Settlement] (IEnumerable`1 source) [0x00000] in <filename unknown>:0
at Verse.GenCollection.TryRandomElement[Settlement] (IEnumerable`1 source, RimWorld.Planet.Settlement& result) [0x00000] in <filename unknown>:0
at Verse.GenCollection.RandomElementWithFallback[Settlement] (IEnumerable`1 source, RimWorld.Planet.Settlement fallback) [0x00000] in <filename unknown>:0
at MoreFactionInteraction.World_Incidents.IncidentWorker_BumperCrop.RandomNearbyGrowerSettlement (Int32 originTile) [0x00000] in <filename unknown>:0
at MoreFactionInteraction.World_Incidents.IncidentWorker_BumperCrop.TryGetRandomAvailableTargetMap (Verse.Map& map) [0x00000] in <filename unknown>:0
at MoreFactionInteraction.World_Incidents.IncidentWorker_BumperCrop.CanFireNowSub (RimWorld.IncidentParms parms) [0x00000] in <filename unknown>:0
at RimWorld.IncidentWorker.CanFireNow (RimWorld.IncidentParms parms, Boolean forced) [0x00000] in <filename unknown>:0
at RimWorld.Storyteller.TryFire (RimWorld.FiringIncident fi) [0x00000] in <filename unknown>:0
at RimWorld.IncidentQueue.IncidentQueueTick () [0x00000] in <filename unknown>:0
at RimWorld.Storyteller.StorytellerTick () [0x00000] in <filename unknown>:0
at Verse.TickManager.DoSingleTick () [0x00000] in <filename unknown>:0
Verse.Log:Error(String, Boolean)

MFI_BumperCropRequest "harvesting request" incident = MoreFactionInteraction.World_Incidents.IncidentWorker_BumperCrop.

I am going to disable the bumper crop incident and clear it from my save game under the queued incidents if it's there and see what happens.

Edit 1: As expected the storyteller choose the MFI_BumperCropRequest aka "harvesting request" and for me it bugged out and refuses to let the other incident I have which is the MFI_reversetraderequest through which is spamming the dev log every single tick which dramatically affects fps. I will now clear it from my save's queued incidents and disable it in the mod files so the storyteller can't choose it and see if that fixes it.

Edit 2: Cleared it from my save's queued incidents and disabled it in the mod files. The dev log is no longer spammed with literally 999 messages about the same error coming from MFI_BumperCropRequest thus I no longer get an fps drop. Now I simply have to wait and see if an incident comes through.

Edit 3: Problem solved. While you lose an incident in the process, I, for one, at least with the mod list I have, never actually saw this event ever. So maybe there's a conflict somewhere but according to dev log this is the only incident that prevents other incidents from occuring.

The issue is the combination of this and rimcities, this event is not compatible with it, youll need to for now remove the incident from the queue in your save and remove the event from the mod files.

I dont even have rimcities so its got nothing to do with that.

I havent had a raid for almost 2 years now.