Added it to an existing save, or is this an older save you didn't play for a few weeks?

There *was* a bug in an earlier version where things kinda... uh.. broke if the Faction Leader was gone. I fixed that one, but it seems similar to what you got.

If not, I see Psychology is having issues. That might be causing this too.

Hey there, i have the same problem.
That's strange because i added it to an existing save but everything worked fine until now ( works for at least 2 week without problem).
I tried to install 7 more mods today then the problem shows up. Tried to load an old save (when everynthing works) without the 7 mods but the problem still show.
The 7 mods was :
Rimhammer 40K
Locks (doors expanded)
Names Gallore
Skilled stonecutting
Mercers's backpack and nanosuit
Fueled Nuclear power generators
Sparkling worlds extension - BMC Hardcore

Oh and i don't have psychology.

Here's the log :

System.NullReferenceException: Object reference not set to an instance of an object
at MoreFactionInteraction.IncidentWorker_SpreadingOutpost.TryExecuteWorker (RimWorld.IncidentParms parms) [0x00000] in <filename unknown>:0
at RimWorld.IncidentWorker.TryExecute (RimWorld.IncidentParms parms) [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)
Verse.TickManager:DoSingleTick()
Verse.TickManager:TickManagerUpdate()
Verse.Game:UpdatePlay()
Verse.Root_Play:Update()

Any clues ?
Thanks
(Great mod by the way)

Fixed for next release, assuming this was caused by a misconfigured faction with a null leader.

Thanks for the report.

Originally posted by Mehni:

Fixed for next release, assuming this was caused by a misconfigured faction with a null leader.

Thanks for the report.

No, thank YOU for fixing it, and thank YOU for the awesome mod, keep it up!

so many outposts and im so ready to take them all down now that winter has gone and spring planting is done. But, my the only two I can send out to get everything done are the only two without pyromaniac, and well its been much improved since b18. The pyros both have chemical fascination so I am hoping that they binge on smokeleaf and not on burning the base down, haha, muhahaha. Ive lost so many games trying to take on the world, loving this mod.

I have the same problem as the original poster. I'm really not sure what I can do to fix it so I'll just start a new colony. Things to know that this happened while I had a caravan out on a mission but they were on the world map and the colony is about 5 ingame years old, I have psychology and sparkling works which adds new world map events and android tiers which adds another pirate faction, I'm not sure if that information helps at all but nonetheless I'll offer it up just incase.
https://imgur.com/gallery/vcTAV06