Добавьте файлы проекта.

NebulaAuth.LegacyConverter/NebulaAuth.LegacyConverter.csproj

@@ -0,0 +1,14 @@
+<Project Sdk="Microsoft.NET.Sdk">
+
+  <PropertyGroup>
+    <OutputType>Exe</OutputType>
+    <TargetFramework>net8.0</TargetFramework>
+    <ImplicitUsings>enable</ImplicitUsings>
+    <Nullable>enable</Nullable>
+  </PropertyGroup>
+
+  <ItemGroup>
+    <ProjectReference Include="..\SteamLibForked\SteamLibForked.csproj" />
+  </ItemGroup>
+
+</Project>

NebulaAuth.LegacyConverter/Program.cs

@@ -0,0 +1,51 @@
+using Newtonsoft.Json;
+using SteamLib.Utility.MaFiles;
+
+var currentPath = Path.GetDirectoryName(System.Reflection.Assembly.GetExecutingAssembly().Location);
+if (currentPath != null)
+    Environment.CurrentDirectory = currentPath;
+
+
+Console.WriteLine(currentPath);
+foreach (var path in args)
+{
+
+    if (Path.Exists(path) == false)
+    {
+        Console.WriteLine($"NOT VALID PATH: '{path}'");
+        continue;
+    }
+    Console.WriteLine("Reading: " + path);
+    try
+    {
+        var text = File.ReadAllText(path);
+        var maf = MafileSerializer.Deserialize(text, out _);
+        var legacy = MafileSerializer.SerializeLegacy(maf, Formatting.Indented);
+        var name = Path.GetFileNameWithoutExtension(path);
+        Write(legacy, name);
+
+        Console.WriteLine("DONE: " + name);
+    }
+    catch (Exception ex)
+    {
+        Console.WriteLine($"ERROR: {ex.Message}");
+        Console.WriteLine(ex);
+    }
+    finally
+    {
+        Console.WriteLine("-----------------------------------------");
+    }
+
+
+}
+
+Console.WriteLine("Press any key to exit...");
+Console.ReadKey();
+
+
+void Write(string maf, string name)
+{
+
+    var path = Path.Combine(name + "_legacy.mafile");
+    File.WriteAllText(path, maf);
+}