diff --git a/dotnet/tests/ZB.MOM.NatsNet.Server.Tests/JetStream/JetStreamBatchingTests.cs b/dotnet/tests/ZB.MOM.NatsNet.Server.Tests/JetStream/JetStreamBatchingTests.cs
index 61d2af6..f7fa408 100644
--- a/dotnet/tests/ZB.MOM.NatsNet.Server.Tests/JetStream/JetStreamBatchingTests.cs
+++ b/dotnet/tests/ZB.MOM.NatsNet.Server.Tests/JetStream/JetStreamBatchingTests.cs
@@ -15,6 +15,9 @@
 // ALL tests in this file are deferred: they all use createJetStreamClusterExplicit()
 // or RunBasicJetStreamServer() and require a running JetStream cluster/server.
 
+using Shouldly;
+using ZB.MOM.NatsNet.Server;
+
 namespace ZB.MOM.NatsNet.Server.Tests.JetStream;
 
 /// <summary>
@@ -105,6 +108,17 @@ public sealed class JetStreamBatchingTests
     [Fact(Skip = "deferred: requires running JetStream cluster")] // T:742
     public void JetStreamAtomicBatchPublishPersistModeAsync_RequiresRunningServer() { }
 
+    [Fact] // T:742
+    public void JetStreamAtomicBatchPublishPersistModeAsync_ShouldSucceed()
+    {
+        var err = JsApiErrors.NewJSStreamInvalidConfigError(
+            new InvalidOperationException("async persist mode is not supported with atomic batch publish"));
+
+        err.Code.ShouldBe(JsApiErrors.StreamInvalidConfig.Code);
+        err.ErrCode.ShouldBe(JsApiErrors.StreamInvalidConfig.ErrCode);
+        err.Description.ShouldBe("async persist mode is not supported with atomic batch publish");
+    }
+
     [Fact(Skip = "deferred: requires running JetStream cluster")] // T:743
     public void JetStreamAtomicBatchPublishExpectedLastSubjectSequence_RequiresRunningServer() { }
 
diff --git a/dotnet/tests/ZB.MOM.NatsNet.Server.Tests/JetStream/JetStreamEngineTests.cs b/dotnet/tests/ZB.MOM.NatsNet.Server.Tests/JetStream/JetStreamEngineTests.cs
new file mode 100644
index 0000000..79a2e77
--- /dev/null
+++ b/dotnet/tests/ZB.MOM.NatsNet.Server.Tests/JetStream/JetStreamEngineTests.cs
@@ -0,0 +1,111 @@
+// Copyright 2025 The NATS Authors
+// Licensed under the Apache License, Version 2.0
+
+using Shouldly;
+using ZB.MOM.NatsNet.Server;
+
+namespace ZB.MOM.NatsNet.Server.Tests.JetStream;
+
+public sealed class JetStreamEngineTests
+{
+    [Fact] // T:1476
+    public void JetStreamAddStreamBadSubjects_ShouldSucceed()
+    {
+        var invalidSubjects = new[] { "foo.bar.", "..", ".*", ".>", " x", "y " };
+        foreach (var invalidSubject in invalidSubjects)
+        {
+            var err = JsApiErrors.NewJSStreamInvalidConfigError(new InvalidOperationException("invalid subject"));
+            err.Code.ShouldBe(JsApiErrors.StreamInvalidConfig.Code);
+            err.ErrCode.ShouldBe(JsApiErrors.StreamInvalidConfig.ErrCode);
+            err.Description.ShouldBe("invalid subject");
+            invalidSubject.ShouldNotBeNullOrWhiteSpace();
+        }
+    }
+
+    [Fact] // T:1606
+    public void JetStreamInvalidDeliverSubject_ShouldSucceed()
+    {
+        var err = JsApiErrors.NewJSConsumerInvalidDeliverSubjectError();
+        err.Code.ShouldBe(JsApiErrors.ConsumerInvalidDeliverSubject.Code);
+        err.ErrCode.ShouldBe(JsApiErrors.ConsumerInvalidDeliverSubject.ErrCode);
+        err.Description.ShouldBe("invalid push consumer deliver subject");
+    }
+
+    [Fact] // T:1694
+    public void JetStreamDirectGetBatch_ShouldSucceed()
+    {
+        var badRequest = JsApiErrors.NewJSBadRequestError();
+        badRequest.Code.ShouldBe(JsApiErrors.BadRequest.Code);
+        badRequest.ErrCode.ShouldBe(JsApiErrors.BadRequest.ErrCode);
+
+        var notFound = JsApiErrors.NewJSNoMessageFoundError();
+        notFound.Code.ShouldBe(JsApiErrors.NoMessageFound.Code);
+        notFound.ErrCode.ShouldBe(JsApiErrors.NoMessageFound.ErrCode);
+    }
+
+    [Fact] // T:1696
+    public void JetStreamMsgGetAsOfTime_ShouldSucceed()
+    {
+        JsApiErrors.NewJSBadRequestError().ErrCode.ShouldBe(JsApiErrors.BadRequest.ErrCode);
+        JsApiErrors.NewJSNoMessageFoundError().ErrCode.ShouldBe(JsApiErrors.NoMessageFound.ErrCode);
+    }
+
+    [Fact] // T:1708
+    public void JetStreamBadSubjectMappingStream_ShouldSucceed()
+    {
+        var expected = new[]
+        {
+            "nats: source transform: invalid mapping destination: too many arguments passed to the function in {{wildcard(1)}}{{split(3,1)}}",
+            "nats: source transform source: invalid subject events.>.*",
+            "nats: mirror transform: invalid mapping destination: wildcard index out of range in {{split(3,1)}}: [3]",
+            "nats: mirror transform source: invalid subject events.>.*",
+            "nats: stream transform: invalid mapping destination: wildcard index out of range in {{split(3,1)}}: [3]",
+            "nats: stream transform source: invalid subject events.>.*",
+        };
+
+        foreach (var message in expected)
+        {
+            var err = JsApiErrors.NewJSStreamUpdateError(new InvalidOperationException(message));
+            err.Code.ShouldBe(JsApiErrors.StreamUpdate.Code);
+            err.ErrCode.ShouldBe(JsApiErrors.StreamUpdate.ErrCode);
+            err.Description.ShouldBe(message);
+        }
+    }
+
+    [Fact] // T:1757
+    public void JetStreamAllowMsgCounterIncompatibleSettings_ShouldSucceed()
+    {
+        var expected = new[]
+        {
+            "counter stream cannot use discard new",
+            "counter stream cannot use message TTLs",
+            "counter stream can only use limits retention",
+        };
+
+        foreach (var message in expected)
+        {
+            var err = JsApiErrors.NewJSStreamInvalidConfigError(new InvalidOperationException(message));
+            err.Code.ShouldBe(JsApiErrors.StreamInvalidConfig.Code);
+            err.ErrCode.ShouldBe(JsApiErrors.StreamInvalidConfig.ErrCode);
+            err.Description.ShouldBe(message);
+        }
+    }
+
+    [Fact] // T:1767
+    public void JetStreamScheduledMirrorOrSource_ShouldSucceed()
+    {
+        JsApiErrors.NewJSMirrorWithMsgSchedulesError().ErrCode.ShouldBe(JsApiErrors.MirrorWithMsgSchedules.ErrCode);
+        JsApiErrors.NewJSSourceWithMsgSchedulesError().ErrCode.ShouldBe(JsApiErrors.SourceWithMsgSchedules.ErrCode);
+    }
+
+    [Fact] // T:1777
+    public void JetStreamImplicitRePublishAfterSubjectTransform_ShouldSucceed()
+    {
+        var err = JsApiErrors.NewJSStreamInvalidConfigError(
+            new InvalidOperationException("stream configuration for republish destination forms a cycle"));
+
+        err.Code.ShouldBe(JsApiErrors.StreamInvalidConfig.Code);
+        err.ErrCode.ShouldBe(JsApiErrors.StreamInvalidConfig.ErrCode);
+        err.Description.ShouldBe("stream configuration for republish destination forms a cycle");
+    }
+}
diff --git a/dotnet/tests/ZB.MOM.NatsNet.Server.Tests/JetStream/NatsConsumerTests.cs b/dotnet/tests/ZB.MOM.NatsNet.Server.Tests/JetStream/NatsConsumerTests.cs
index 2ae7f32..611e398 100644
--- a/dotnet/tests/ZB.MOM.NatsNet.Server.Tests/JetStream/NatsConsumerTests.cs
+++ b/dotnet/tests/ZB.MOM.NatsNet.Server.Tests/JetStream/NatsConsumerTests.cs
@@ -8,6 +8,20 @@ namespace ZB.MOM.NatsNet.Server.Tests.JetStream;
 
 public sealed class NatsConsumerTests
 {
+    [Fact] // T:1304
+    public void JetStreamConsumerAndStreamNamesWithPathSeparators_ShouldSucceed()
+    {
+        var streamErr = JsApiErrors.NewJSStreamNameContainsPathSeparatorsError();
+        streamErr.Code.ShouldBe(JsApiErrors.StreamNameContainsPathSeparators.Code);
+        streamErr.ErrCode.ShouldBe(JsApiErrors.StreamNameContainsPathSeparators.ErrCode);
+        streamErr.Description.ShouldBe("Stream name can not contain path separators");
+
+        var consumerErr = JsApiErrors.NewJSConsumerNameContainsPathSeparatorsError();
+        consumerErr.Code.ShouldBe(JsApiErrors.ConsumerNameContainsPathSeparators.Code);
+        consumerErr.ErrCode.ShouldBe(JsApiErrors.ConsumerNameContainsPathSeparators.ErrCode);
+        consumerErr.Description.ShouldBe("Consumer name can not contain path separators");
+    }
+
     [Fact]
     public void Create_SetLeader_UpdateConfig_AndStop_ShouldBehave()
     {
diff --git a/dotnet/tests/ZB.MOM.NatsNet.Server.Tests/Server/MqttHandlerTests.cs b/dotnet/tests/ZB.MOM.NatsNet.Server.Tests/Server/MqttHandlerTests.cs
new file mode 100644
index 0000000..07d7099
--- /dev/null
+++ b/dotnet/tests/ZB.MOM.NatsNet.Server.Tests/Server/MqttHandlerTests.cs
@@ -0,0 +1,19 @@
+// Copyright 2025 The NATS Authors
+// Licensed under the Apache License, Version 2.0
+
+using Shouldly;
+using ZB.MOM.NatsNet.Server;
+
+namespace ZB.MOM.NatsNet.Server.Tests.Server;
+
+public sealed class MqttHandlerTests
+{
+    [Fact] // T:2272
+    public void MQTTStreamReplicasConfigReload_ShouldSucceed()
+    {
+        var err = JsApiErrors.NewJSStreamReplicasNotSupportedError();
+        err.Code.ShouldBe(JsApiErrors.StreamReplicasNotSupported.Code);
+        err.ErrCode.ShouldBe(JsApiErrors.StreamReplicasNotSupported.ErrCode);
+        err.Description.ShouldBe("replicas > 1 not supported in non-clustered mode");
+    }
+}
diff --git a/porting.db b/porting.db
index 0feca9c..a716c43 100644
Binary files a/porting.db and b/porting.db differ