diff --git a/.github/workflows/feature_branches.yml b/.github/workflows/feature_branches.yml
index 7199d5bb..587b9a08 100644
--- a/.github/workflows/feature_branches.yml
+++ b/.github/workflows/feature_branches.yml
@@ -22,7 +22,7 @@ jobs:
       - name: Setup .NET Core
         uses: actions/setup-dotnet@v4
         with:
-          dotnet-version: 6.0.201
+          dotnet-version: 8
       - name: Build/Check for compile errors (dotnet build)
         run: dotnet build --configuration Release --version-suffix "${{github.sha}}"
       - name: Run Unit Tests (dotnet test)
diff --git a/BO4E/meta/LenientConverters/LenientGeraetemerkmalGasConverter.cs b/BO4E/meta/LenientConverters/LenientGeraetemerkmalGasConverter.cs
index b68b3105..31256b35 100644
--- a/BO4E/meta/LenientConverters/LenientGeraetemerkmalGasConverter.cs
+++ b/BO4E/meta/LenientConverters/LenientGeraetemerkmalGasConverter.cs
@@ -12,7 +12,7 @@ namespace BO4E.meta.LenientConverters;
 public class LenientGeraetemerkmalGasConverter : JsonConverter
 {
     /// <inheritdoc cref="JsonConverter.CanWrite" />
-    public override bool CanWrite => false;
+    public override bool CanWrite => true;
 
     /// <inheritdoc cref="JsonConverter.CanConvert(Type)" />
     public override bool CanConvert(Type objectType)
@@ -41,7 +41,10 @@ JsonSerializer serializer
                 rawValue = reader.Value?.ToString();
                 break;
         }
-
+        if (string.IsNullOrEmpty(rawValue))
+        {
+            return null;
+        }
         try
         {
             return Enums.Parse<Geraetemerkmal>(rawValue);
@@ -59,6 +62,6 @@ JsonSerializer serializer
     /// <inheritdoc cref="JsonConverter.WriteJson(JsonWriter, object, JsonSerializer)" />
     public override void WriteJson(JsonWriter writer, object value, JsonSerializer serializer)
     {
-        throw new NotImplementedException();
+        writer.WriteRawValue("\"" + value.ToString() + "\"");
     }
 }
diff --git a/BO4E/meta/LenientConverters/LenientSystemTextGeraetemerkmalGasConverter.cs b/BO4E/meta/LenientConverters/LenientSystemTextGeraetemerkmalGasConverter.cs
index 715ff36a..81c13199 100644
--- a/BO4E/meta/LenientConverters/LenientSystemTextGeraetemerkmalGasConverter.cs
+++ b/BO4E/meta/LenientConverters/LenientSystemTextGeraetemerkmalGasConverter.cs
@@ -57,13 +57,6 @@ JsonSerializerOptions options
     )
     {
         var stringValue = value.ToString();
-        var match = GasPrefixRegex.Match(stringValue);
-        if (!match.Success)
-        {
-            writer.WriteStringValue(stringValue);
-            return;
-        }
-        var rest = match.Groups["rest"].Value;
-        writer.WriteStringValue(rest);
+        writer.WriteStringValue(stringValue);
     }
 }
diff --git a/BO4E/meta/LenientConverters/LenientSystemTextNullableGeraetemerkmalGasConverter.cs b/BO4E/meta/LenientConverters/LenientSystemTextNullableGeraetemerkmalGasConverter.cs
index 68c5a5a3..ffa654be 100644
--- a/BO4E/meta/LenientConverters/LenientSystemTextNullableGeraetemerkmalGasConverter.cs
+++ b/BO4E/meta/LenientConverters/LenientSystemTextNullableGeraetemerkmalGasConverter.cs
@@ -62,16 +62,8 @@ JsonSerializerOptions options
     {
         if (value.HasValue)
         {
-            // Remove the "GAS_" prefix if it exists
-            var stringValue = value.Value.ToString();
-            var match = GasPrefixRegex.Match(stringValue);
-            if (!match.Success)
-            {
-                writer.WriteStringValue(stringValue);
-                return;
-            }
-            var rest = match.Groups["rest"].Value;
-            writer.WriteStringValue(rest);
+            var stringValue = value.ToString();
+            writer.WriteStringValue(stringValue);
         }
         else
         {
diff --git a/BO4E/protobuf-files/bo4e.proto b/BO4E/protobuf-files/bo4e.proto
index b10594b3..10ec5447 100644
--- a/BO4E/protobuf-files/bo4e.proto
+++ b/BO4E/protobuf-files/bo4e.proto
@@ -329,6 +329,7 @@ enum Energierichtung {
    AUSSP = 0;
    EINSP = 1;
    RUHEND = 2;
+   KUNDENANLAGE = 3;
 }
 message Erreichbarkeit {
    option (.protobuf_net.msgopt).namespace = "BO4E.COM";
@@ -961,7 +962,7 @@ message Marktlokation {
    Geschaeftspartner Endkunde = 17;
    Adresse Lokationsadresse = 18;
    Geokoordinaten Geoadresse = 19;
-   Katasteradresse Katasterinformation = 20;
+   repeated Katasteradresse Katasterinformation = 20;
    repeated Messlokationszuordnung ZugehoerigeMesslokationen = 28;
    repeated Netznutzungsabrechnungsdaten Netznutzungsabrechnungsdaten = 37;
    Sperrstatus Sperrstatus = 38;
diff --git a/BO4ETestProject/TestGeraetemerkmalConverter.cs b/BO4ETestProject/TestGeraetemerkmalConverter.cs
index a6d95628..e4d75657 100644
--- a/BO4ETestProject/TestGeraetemerkmalConverter.cs
+++ b/BO4ETestProject/TestGeraetemerkmalConverter.cs
@@ -1,3 +1,4 @@
+using System.Collections.Generic;
 using System.Text.Json.Serialization;
 using BO4E.ENUM;
 using BO4E.meta.LenientConverters;
@@ -84,6 +85,27 @@ public void TestNewtonsoft_Success_Nullable()
         result.Merkmal.Should().Be(Geraetemerkmal.GAS_G4);
     }
 
+    [TestMethod]
+    public void TestNewtonsoft_Success_Nullable_Serialization()
+    {
+        var myInstance = new SomethingWithANullableGeraetemerkmal()
+        {
+            Merkmal = Geraetemerkmal.GAS_G4,
+        };
+        var result = JsonConvert.SerializeObject(
+            myInstance,
+            new JsonSerializerSettings()
+            {
+                Converters = new List<Newtonsoft.Json.JsonConverter>()
+                {
+                    new LenientGeraetemerkmalGasConverter(),
+                    new Newtonsoft.Json.Converters.StringEnumConverter(),
+                },
+            }
+        );
+        result.Should().NotBeNullOrWhiteSpace().And.Contain("\"GAS_G4\"").And.NotContain("\"G4\"");
+    }
+
     [TestMethod]
     public void TestNewtonsoft_Success_Nullable_WASSER_MWZW()
     {
@@ -120,6 +142,21 @@ public void TestSystemText_Success_NonNullable()
         result.Merkmal.Should().Be(Geraetemerkmal.GAS_G4);
     }
 
+    [TestMethod]
+    public void TestSystemText_Success_NonNullable_Serialization()
+    {
+        var myInstance = new SomethingWithANullableGeraetemerkmal()
+        {
+            Merkmal = Geraetemerkmal.GAS_G4,
+        };
+        var settings = new System.Text.Json.JsonSerializerOptions()
+        {
+            Converters = { new LenientSystemTextGeraetemerkmalGasConverter() },
+        };
+        var result = System.Text.Json.JsonSerializer.Serialize(myInstance, settings);
+        result.Should().NotBeNullOrWhiteSpace().And.Contain("\"GAS_G4\"").And.NotContain("\"G4\"");
+    }
+
     [TestMethod]
     public void TestSystemText_Success_NonNullable_WASSER_MWZW()
     {
@@ -172,7 +209,7 @@ public void TestSystemText_Write_NonNullable()
         };
         var instance = new SomethingWithAGeraetemerkmal { Merkmal = Geraetemerkmal.GAS_G4 };
         var json = System.Text.Json.JsonSerializer.Serialize(instance, settings);
-        json.Should().Be("{\"merkmal\":\"G4\"}");
+        json.Should().Be($"{{\"merkmal\":\"{Geraetemerkmal.GAS_G4.ToString()}\"}}");
     }
 
     [TestMethod]
@@ -187,7 +224,7 @@ public void TestSystemText_Write_Nullable()
             Merkmal = Geraetemerkmal.GAS_G2P5,
         };
         var json = System.Text.Json.JsonSerializer.Serialize(instance, settings);
-        json.Should().Be("{\"merkmal\":\"G2P5\"}");
+        json.Should().Be("{\"merkmal\":\"GAS_G2P5\"}");
     }
 
     [TestMethod]