diff --git a/.github/workflows/library_interop_tests.yml b/.github/workflows/library_interop_tests.yml
index 8e6beaca8..40e7a1924 100644
--- a/.github/workflows/library_interop_tests.yml
+++ b/.github/workflows/library_interop_tests.yml
@@ -193,17 +193,6 @@ jobs:
       # #     # NET_41_VECTOR_PATH=$GITHUB_WORKSPACE/net41/vectors
       # #     Set-Location -Path "$env:GITHUB_WORKSPACE\net41\vectors"
       # #     Compress-Archive -Path "$env:GITHUB_WORKSPACE\net41\vectors\*" -DestinationPath "$env:GITHUB_WORKSPACE\net41\vectors\net41.zip"        
-
-      - name: Fetch Python 2.3.0 Test Vectors
-        working-directory: ./
-        shell: bash
-        run: |
-          PYTHON_23_VECTOR_PATH=$GITHUB_WORKSPACE/python23/vectors
-          mkdir -p $PYTHON_23_VECTOR_PATH
-          DOWNLOAD_NAME=python23.zip
-          curl --no-progress-meter --output $DOWNLOAD_NAME --location $VECTORS_URL
-          unzip -o -qq $DOWNLOAD_NAME  -d $PYTHON_23_VECTOR_PATH
-          rm  $DOWNLOAD_NAME
       
       - name: Generate Test Vectors with .NET Framework net6.0
         # TODO Post-#619: Fix Zip file creation on Windows
@@ -214,8 +203,6 @@ jobs:
           NET_41_VECTOR_PATH=net41/vectors
           mkdir -p $NET_41_VECTOR_PATH
           GEN_PATH=runtimes/net/TestVectorsNative/TestVectorGenerator
-          PYTHON_23_VECTOR_PATH=$GITHUB_WORKSPACE/python23/vectors
-          DAFNY_AWS_ESDK_TEST_VECTOR_MANIFEST_PATH="$PYTHON_23_VECTOR_PATH/manifest.json" \
           dotnet run --project $GEN_PATH --framework net6.0 -- \
             --encrypt-manifest $GEN_PATH/resources/0006-awses-message-decryption-generation.v2.json \
             --output-dir $NET_41_VECTOR_PATH
diff --git a/AwsEncryptionSDK/runtimes/net/TestVectorsNative/TestVectorLib/MaterialProviderFactory.cs b/AwsEncryptionSDK/runtimes/net/TestVectorsNative/TestVectorLib/MaterialProviderFactory.cs
index ac7e36a89..30875bd49 100644
--- a/AwsEncryptionSDK/runtimes/net/TestVectorsNative/TestVectorLib/MaterialProviderFactory.cs
+++ b/AwsEncryptionSDK/runtimes/net/TestVectorsNative/TestVectorLib/MaterialProviderFactory.cs
@@ -166,20 +166,6 @@ private static IKeyring CreateKeyring(MasterKey keyInfo, Key key, CryptoOperatio
             }
 
             if (keyInfo.Type == "aws-kms-hierarchy") {
-                // Convert JSON to bytes for KeyVectors input
-                string jsonString = JsonConvert.SerializeObject(keyInfo);
-
-                var stream = new MemoryStream();
-                var writer = new StreamWriter(stream);
-                writer.Write(jsonString);
-                writer.Flush();
-                stream.Position = 0;
-
-                // Create KeyVectors keyring
-                var getKeyDescriptionInput = new GetKeyDescriptionInput
-                {
-                    Json = stream
-                };
 
                 // Lazily create a singleton KeyVectors client.
                 // KeyVectors manifest is only required if a test vector specifies a hierarchy keyring.
@@ -202,6 +188,21 @@ private static IKeyring CreateKeyring(MasterKey keyInfo, Key key, CryptoOperatio
                     singletonKeyVectors = new(keyVectorsConfig);
                 }
 
+                // Convert JSON to bytes for KeyVectors input
+                string jsonString = JsonConvert.SerializeObject(keyInfo);
+
+                var stream = new MemoryStream();
+                var writer = new StreamWriter(stream);
+                writer.Write(jsonString);
+                writer.Flush();
+                stream.Position = 0;
+
+                // Create KeyVectors keyring
+                var getKeyDescriptionInput = new GetKeyDescriptionInput
+                {
+                    Json = stream
+                };
+
                 var desc = singletonKeyVectors.GetKeyDescription(getKeyDescriptionInput);
 
                 var testVectorKeyringInput = new TestVectorKeyringInput