diff --git a/EDPlayerJournal/CombatZones.cs b/EDPlayerJournal/CombatZones.cs
index 0eec1c9..3c59477 100644
--- a/EDPlayerJournal/CombatZones.cs
+++ b/EDPlayerJournal/CombatZones.cs
@@ -43,7 +43,7 @@ public class CombatZones {
     /// Returns the given combat zone difficulty as an integer, so it can be sorted.
     /// 0 = lowest difficulty, 1 = medium and so forth.
     /// </summary>
-    public static int? DifficultyRank(string difficulty) {
+    public static int? DifficultyRank(string? difficulty) {
         Dictionary<string, int> ranks = new() {
             { DifficultyLow, 0 },
             { DifficultyMedium, 1 },
@@ -51,6 +51,10 @@ public class CombatZones {
             { DifficultyVeryHigh, 3 }
         };
 
+        if (difficulty == null ) {
+            return null;
+        }
+
         if (ranks.TryGetValue(difficulty, out int rank)) {
             return rank;
         }
diff --git a/EliteBGS/LogGenerator/CombatZoneFormat.cs b/EliteBGS/LogGenerator/CombatZoneFormat.cs
index e849bd8..33aa726 100644
--- a/EliteBGS/LogGenerator/CombatZoneFormat.cs
+++ b/EliteBGS/LogGenerator/CombatZoneFormat.cs
@@ -9,7 +9,7 @@ class CombatZoneFormat : LogFormatter {
     public string GenerateLog(Objective objective) {
         var logs = objective
             .EnabledOfType<CombatZone>()
-            .OrderBy(x => CombatZones.DifficultyRank(x.Grade))
+            .OrderBy(x => (CombatZones.DifficultyRank(x.Grade) ?? 0))
             .GroupBy(x => new { x.Type, x.Grade })
             .ToDictionary(x => x.Key, x => x.ToList())
             ;
@@ -48,7 +48,7 @@ class CombatZoneFormat : LogFormatter {
     public string GenerateSummary(Objective objective) {
         var logs = objective
             .EnabledOfType<CombatZone>()
-            .OrderBy(x => CombatZones.DifficultyRank(x.Grade))
+            .OrderBy(x => (CombatZones.DifficultyRank(x.Grade) ?? 0))
             .GroupBy(x => new { x.Type, x.Grade })
             .ToDictionary(x => x.Key, x => x.ToList())
             ;