diff --git a/ElectronicObserver/Data/Battle/Phase/PhaseTorpedo.cs b/ElectronicObserver/Data/Battle/Phase/PhaseTorpedo.cs
index a6f3e8f92..f034ba5ae 100644
--- a/ElectronicObserver/Data/Battle/Phase/PhaseTorpedo.cs
+++ b/ElectronicObserver/Data/Battle/Phase/PhaseTorpedo.cs
@@ -111,27 +111,38 @@ public override void EmulateBattle(int[] hps, int[] damages)
 
 
 
-		private T[] GetConcatArray<T>(string friendName, string enemyName, T defaultValue)
+		private T[] GetConcatArray<T>(string friendName, string enemyName, T defaultValue) where T : struct
 		{
-			var friend = (T[])TorpedoData[friendName];
-			var enemy = (T[])TorpedoData[enemyName];
+			var friend = ConvertToArray<T>(TorpedoData[friendName], 12, defaultValue);
+			var enemy = ConvertToArray<T>(TorpedoData[enemyName], 12, defaultValue);
 
 			var ret = new T[24];
 
 			for (int i = 0; i < 12; i++)
 			{
-				if (i < friend.Length)
-					ret[i] = friend[i];
-				else
-					ret[i] = defaultValue;
-
-				if (i < enemy.Length)
-					ret[i + 12] = enemy[i];
-				else
-					ret[i + 12] = defaultValue;
+				ret[i] = friend[i];
+				ret[i + 12] = enemy[i];
 			}
 
 			return ret;
 		}
+
+		/// <summary>
+		/// 基本的には `(T[])json` と等価ですが、特定の状況下におけるデータエラーを回避するための実装が含まれています
+		/// https://github.com/andanteyk/ElectronicObserver/issues/294
+		/// </summary>
+		private static T[] ConvertToArray<T>(dynamic json, int maxLength, T defaultValue) where T : struct
+		{
+			var ret = Enumerable.Repeat(defaultValue, maxLength).ToArray();
+			int i = 0;
+			foreach (var member in json)
+			{
+				ret[i++ % maxLength] =
+					member is KeyValuePair<string, dynamic> pair ? (T)pair.Value :
+					member != null ? (T)member :
+					default(T);
+			}
+			return ret;
+		}
 	}
 }
diff --git a/ElectronicObserver/Utility/SoftwareInformation.cs b/ElectronicObserver/Utility/SoftwareInformation.cs
index a8090dbdb..7f244cb5a 100644
--- a/ElectronicObserver/Utility/SoftwareInformation.cs
+++ b/ElectronicObserver/Utility/SoftwareInformation.cs
@@ -29,20 +29,20 @@ public static class SoftwareInformation
 		/// <summary>
 		/// バージョン(日本語, ソフトウェア名を含みます)
 		/// </summary>
-		public static string VersionJapanese => SoftwareNameJapanese + "四七型";
+		public static string VersionJapanese => SoftwareNameJapanese + "四七型改";
 
 
 		/// <summary>
 		/// バージョン(英語)
 		/// </summary>
-		public static string VersionEnglish => "4.7.0";
+		public static string VersionEnglish => "4.7.1";
 
 
 
 		/// <summary>
 		/// 更新日時
 		/// </summary>
-		public static DateTime UpdateTime => DateTimeHelper.CSVStringToTime("2021/09/19 18:30:00");
+		public static DateTime UpdateTime => DateTimeHelper.CSVStringToTime("2021/11/23 18:30:00");