Read the magic and throw an error if it's wrong.

Program.cs

@@ -11,10 +11,13 @@ namespace LuckCatchers_Extractor
         static void Main(string[] args)
         {
             br = new(File.OpenRead(args[0]));
-            br.BaseStream.Position = 8;
+            if (new string(br.ReadChars(8)) != "VOLUME0\0")
+                throw new System.Exception("This is not a LuckCatchers res file.");
 
-            System.Collections.Generic.List<Subfile> subfiles = new();
+            System.Collections.Generic.List<Subfile> subfiles = new()
-            subfiles.Add(new());
+            {
+                new()
+            };
             for(int i = 0; i < subfiles[0].size - 1; i++)
                 subfiles.Add(new());