With this mod installed, I get the following error log every time a raid spawns:

Getting random element from empty collection.
UnityEngine.StackTraceUtility:ExtractStackTrace ()
Verse.Log:Warning (string)
Verse.GenCollection:RandomElement<Verse.Thing> (System.Collections.Generic.IEnumerable`1<Verse.Thing>)
SingalTower.Patch_IncidentWork:Prefix (RimWorld.IncidentWorker,RimWorld.IncidentParms)
(wrapper dynamic-method) RimWorld.IncidentWorker:RimWorld.IncidentWorker.TryExecute_Patch2 (RimWorld.IncidentWorker,RimWorld.IncidentParms)
Verse.DebugActionsIncidents:DoRaid (RimWorld.IncidentParms)
Verse.DebugActionsIncidents/<>c__DisplayClass2_2:<ExecuteRaidWithFaction>b__2 ()
Verse.Dialog_DebugOptionLister:DebugAction (string,System.Action,bool)
Verse.Dialog_DebugOptionListLister:DoListingItems ()
Verse.Dialog_OptionLister:DoWindowContents (UnityEngine.Rect)
Verse.Window:InnerWindowOnGUI (int)
UnityEngine.GUI:CallWindowDelegate (UnityEngine.GUI/WindowFunction,int,int,UnityEngine.GUISkin,int,single,single,UnityEngine.GUIStyle)

I believe the misspelled "SingalTower.Patch" line may have something to do with it.