Do not -1 GetNumGroupMembers, party UnitIdCache includes player.

core/gears.lua

@@ -742,7 +742,7 @@ local hasGroupMemberInCombat = function()
 			end
 		end
 	else
-		local amountOfPartyMembers = GetNumGroupMembers() + 1
+		local amountOfPartyMembers = GetNumGroupMembers()
 		for i, unitId in ipairs(Details222.UnitIdCache.Party) do
 			if (i <= amountOfPartyMembers) then
 				if (UnitAffectingCombat(unitId)) then

core/parser.lua

@@ -5173,7 +5173,7 @@ local SPELL_POWER_PAIN = SPELL_POWER_PAIN or (PowerEnum and PowerEnum.Pain) or 1
 
 			elseif (IsInGroup()) then
 				local unitIdCache = Details222.UnitIdCache.Party
-				for i = 1, 4 do
+				for i = 1, 5 do
 					local unitId = unitIdCache[i]
 					local guid = UnitGUID(unitId)
 					if (guid) then
@@ -6258,7 +6258,7 @@ local SPELL_POWER_PAIN = SPELL_POWER_PAIN or (PowerEnum and PowerEnum.Pain) or 1
 
 		elseif (IsInGroup()) then
 			local unitIdCache = Details222.UnitIdCache.Party
-			for i = 1, GetNumGroupMembers()-1 do
+			for i = 1, GetNumGroupMembers() do
 				local unitId = unitIdCache[i]
 
 				local unitName = GetUnitName(unitId, true)

core/util.lua

@@ -1288,7 +1288,7 @@ end
 
 		elseif (IsInGroup()) then
 			local unitIdCache = Details222.UnitIdCache.Party
-			for i = 1, GetNumGroupMembers()-1, 1 do
+			for i = 1, GetNumGroupMembers(), 1 do
 				if (UnitAffectingCombat(unitIdCache[i])) then
 					return true
 				end