diff --git a/server/jetstream.go b/server/jetstream.go
index 1565243a12d..e570f697750 100644
--- a/server/jetstream.go
+++ b/server/jetstream.go
@@ -1348,8 +1348,12 @@ func (a *Account) EnableJetStream(limits map[string]JetStreamAccountLimits) erro
 			var offlineReason string
 			if !supported {
 				apiLevel := getRequiredApiLevel(cfg.Metadata)
-				offlineReason = fmt.Sprintf("unsupported - required API level: %s, current API level: %d", apiLevel, JSApiLevel)
-				s.Warnf("  Detected unsupported stream '%s > %s', delete the stream or upgrade the server to API level %s", a.Name, cfg.StreamConfig.Name, apiLevel)
+				if strictErr != nil {
+					offlineReason = fmt.Sprintf("unsupported - config error: %s", strings.TrimPrefix(err.Error(), "json: "))
+				} else {
+					offlineReason = fmt.Sprintf("unsupported - required API level: %s, current API level: %d", apiLevel, JSApiLevel)
+				}
+				s.Warnf("  Detected unsupported stream '%s > %s': %s", a.Name, cfg.StreamConfig.Name, offlineReason)
 			} else {
 				offlineReason = fmt.Sprintf("decoding error: %v", strictErr)
 				s.Warnf("  Error unmarshalling stream metafile %q: %v", metafile, strictErr)
@@ -1588,8 +1592,12 @@ func (a *Account) EnableJetStream(limits map[string]JetStreamAccountLimits) erro
 				var offlineReason string
 				if !supported {
 					apiLevel := getRequiredApiLevel(cfg.Metadata)
-					offlineReason = fmt.Sprintf("unsupported - required API level: %s, current API level: %d", apiLevel, JSApiLevel)
-					s.Warnf("  Detected unsupported consumer '%s > %s > %s', delete the consumer or upgrade the server to API level %s", a.Name, e.mset.name(), cfg.Name, apiLevel)
+					if strictErr != nil {
+						offlineReason = fmt.Sprintf("unsupported - config error: %s", strings.TrimPrefix(err.Error(), "json: "))
+					} else {
+						offlineReason = fmt.Sprintf("unsupported - required API level: %s, current API level: %d", apiLevel, JSApiLevel)
+					}
+					s.Warnf("  Detected unsupported consumer '%s > %s > %s': %s", a.Name, e.mset.name(), cfg.Name, offlineReason)
 				} else {
 					offlineReason = fmt.Sprintf("decoding error: %v", strictErr)
 					s.Warnf("  Error unmarshalling consumer metafile %q: %v", metafile, strictErr)
@@ -1599,7 +1607,7 @@ func (a *Account) EnableJetStream(limits map[string]JetStreamAccountLimits) erro
 					if !e.mset.closed.Load() {
 						s.Warnf("  Stopping unsupported stream '%s > %s'", a.Name, e.mset.name())
 						e.mset.mu.Lock()
-						e.mset.offlineReason = "stopped"
+						e.mset.offlineReason = fmt.Sprintf("stopped - unsupported consumer %q", cfg.Name)
 						e.mset.mu.Unlock()
 						e.mset.stop(false, false)
 					}
diff --git a/server/jetstream_cluster.go b/server/jetstream_cluster.go
index 00ba6c5fc03..1cef7348847 100644
--- a/server/jetstream_cluster.go
+++ b/server/jetstream_cluster.go
@@ -162,9 +162,15 @@ type unsupportedStreamAssignment struct {
 	infoSub *subscription
 }
 
-func newUnsupportedStreamAssignment(s *Server, sa *streamAssignment) *unsupportedStreamAssignment {
+func newUnsupportedStreamAssignment(s *Server, sa *streamAssignment, err error) *unsupportedStreamAssignment {
 	reason := "stopped"
-	if sa.Config != nil && !supportsRequiredApiLevel(sa.Config.Metadata) {
+	if err != nil {
+		if errstr := err.Error(); strings.HasPrefix(errstr, "json:") {
+			reason = fmt.Sprintf("unsupported - config error: %s", strings.TrimPrefix(err.Error(), "json: "))
+		} else {
+			reason = fmt.Sprintf("stopped - %s", errstr)
+		}
+	} else if sa.Config != nil && !supportsRequiredApiLevel(sa.Config.Metadata) {
 		if req := getRequiredApiLevel(sa.Config.Metadata); req != _EMPTY_ {
 			reason = fmt.Sprintf("unsupported - required API level: %s, current API level: %d", req, JSApiLevel)
 		}
@@ -240,9 +246,15 @@ type unsupportedConsumerAssignment struct {
 	infoSub *subscription
 }
 
-func newUnsupportedConsumerAssignment(ca *consumerAssignment) *unsupportedConsumerAssignment {
+func newUnsupportedConsumerAssignment(ca *consumerAssignment, err error) *unsupportedConsumerAssignment {
 	reason := "stopped"
-	if ca.Config != nil && !supportsRequiredApiLevel(ca.Config.Metadata) {
+	if err != nil {
+		if errstr := err.Error(); strings.HasPrefix(errstr, "json:") {
+			reason = fmt.Sprintf("unsupported - config error: %s", strings.TrimPrefix(err.Error(), "json: "))
+		} else {
+			reason = fmt.Sprintf("stopped - %s", errstr)
+		}
+	} else if ca.Config != nil && !supportsRequiredApiLevel(ca.Config.Metadata) {
 		if req := getRequiredApiLevel(ca.Config.Metadata); req != _EMPTY_ {
 			reason = fmt.Sprintf("unsupported - required API level: %s, current API level: %d", getRequiredApiLevel(ca.Config.Metadata), JSApiLevel)
 		}
@@ -4003,8 +4015,7 @@ func (js *jetStream) processStreamAssignment(sa *streamAssignment) {
 	// If unsupported, we can't register any further.
 	if sa.unsupported != nil {
 		sa.unsupported.setupInfoSub(s, sa)
-		apiLevel := getRequiredApiLevel(sa.Config.Metadata)
-		s.Warnf("Detected unsupported stream '%s > %s', delete the stream or upgrade the server to API level %s", accName, stream, apiLevel)
+		s.Warnf("Detected unsupported stream '%s > %s': %s", accName, stream, sa.unsupported.reason)
 		js.mu.Unlock()
 
 		// Need to stop the stream, we can't keep running with an old config.
@@ -4133,8 +4144,7 @@ func (js *jetStream) processUpdateStreamAssignment(sa *streamAssignment) {
 	// If unsupported, we can't register any further.
 	if sa.unsupported != nil {
 		sa.unsupported.setupInfoSub(s, sa)
-		apiLevel := getRequiredApiLevel(sa.Config.Metadata)
-		s.Warnf("Detected unsupported stream '%s > %s', delete the stream or upgrade the server to API level %s", accName, stream, apiLevel)
+		s.Warnf("Detected unsupported stream '%s > %s': %s", accName, stream, sa.unsupported.reason)
 		js.mu.Unlock()
 
 		// Need to stop the stream, we can't keep running with an old config.
@@ -4815,12 +4825,11 @@ func (js *jetStream) processConsumerAssignment(ca *consumerAssignment) {
 	// If unsupported, we can't register any further.
 	if ca.unsupported != nil {
 		ca.unsupported.setupInfoSub(s, ca)
-		apiLevel := getRequiredApiLevel(ca.Config.Metadata)
-		s.Warnf("Detected unsupported consumer '%s > %s > %s', delete the consumer or upgrade the server to API level %s", accName, stream, ca.Name, apiLevel)
+		s.Warnf("Detected unsupported consumer '%s > %s > %s': %s", accName, stream, ca.Name, ca.unsupported.reason)
 
 		// Mark stream as unsupported as well
 		if sa.unsupported == nil {
-			sa.unsupported = newUnsupportedStreamAssignment(s, sa)
+			sa.unsupported = newUnsupportedStreamAssignment(s, sa, fmt.Errorf("unsupported consumer %q", ca.Name))
 		}
 		sa.unsupported.setupInfoSub(s, sa)
 		js.mu.Unlock()
@@ -8008,20 +8017,21 @@ func decodeStreamAssignment(s *Server, buf []byte) (*streamAssignment, error) {
 func decodeStreamAssignmentConfig(s *Server, sa *streamAssignment) error {
 	var unsupported bool
 	var cfg StreamConfig
+	var err error
 	decoder := json.NewDecoder(bytes.NewReader(sa.ConfigJSON))
 	decoder.DisallowUnknownFields()
-	if err := decoder.Decode(&cfg); err != nil {
+	if err = decoder.Decode(&cfg); err != nil {
 		unsupported = true
 		cfg = StreamConfig{}
-		if err = json.Unmarshal(sa.ConfigJSON, &cfg); err != nil {
-			return err
+		if err2 := json.Unmarshal(sa.ConfigJSON, &cfg); err2 != nil {
+			return err2
 		}
 	}
 	sa.Config = &cfg
 	fixCfgMirrorWithDedupWindow(sa.Config)
 
-	if unsupported || (sa.Config != nil && !supportsRequiredApiLevel(sa.Config.Metadata)) {
-		sa.unsupported = newUnsupportedStreamAssignment(s, sa)
+	if unsupported || err != nil || (sa.Config != nil && !supportsRequiredApiLevel(sa.Config.Metadata)) {
+		sa.unsupported = newUnsupportedStreamAssignment(s, sa, err)
 	}
 	return nil
 }
@@ -8472,18 +8482,19 @@ func decodeConsumerAssignment(buf []byte) (*consumerAssignment, error) {
 func decodeConsumerAssignmentConfig(ca *consumerAssignment) error {
 	var unsupported bool
 	var cfg ConsumerConfig
+	var err error
 	decoder := json.NewDecoder(bytes.NewReader(ca.ConfigJSON))
 	decoder.DisallowUnknownFields()
-	if err := decoder.Decode(&cfg); err != nil {
+	if err = decoder.Decode(&cfg); err != nil {
 		unsupported = true
 		cfg = ConsumerConfig{}
-		if err = json.Unmarshal(ca.ConfigJSON, &cfg); err != nil {
-			return err
+		if err2 := json.Unmarshal(ca.ConfigJSON, &cfg); err2 != nil {
+			return err2
 		}
 	}
 	ca.Config = &cfg
-	if unsupported || (ca.Config != nil && !supportsRequiredApiLevel(ca.Config.Metadata)) {
-		ca.unsupported = newUnsupportedConsumerAssignment(ca)
+	if unsupported || err != nil || (ca.Config != nil && !supportsRequiredApiLevel(ca.Config.Metadata)) {
+		ca.unsupported = newUnsupportedConsumerAssignment(ca, err)
 	}
 	return nil
 }
diff --git a/server/jetstream_cluster_1_test.go b/server/jetstream_cluster_1_test.go
index 6912ef791d8..6d1ca28e4b3 100644
--- a/server/jetstream_cluster_1_test.go
+++ b/server/jetstream_cluster_1_test.go
@@ -9714,7 +9714,7 @@ func TestJetStreamClusterOfflineStreamAndConsumerAfterAssetCreateOrUpdate(t *tes
 
 		// Stream should also be reported as offline.
 		// Specifically, as "stopped" because it's still supported, but can't run due to the unsupported consumer.
-		expectStreamInfo("stopped", "DowngradeConsumerTest")
+		expectStreamInfo("stopped - unsupported consumer \"DowngradeConsumerTest\"", "DowngradeConsumerTest")
 	}
 
 	// Consumer should be reported as offline, but healthz should report healthy to not block downgrades.
diff --git a/server/jetstream_test.go b/server/jetstream_test.go
index cf1ba2211cb..6762f4fcb86 100644
--- a/server/jetstream_test.go
+++ b/server/jetstream_test.go
@@ -21951,7 +21951,7 @@ func TestJetStreamOfflineStreamAndConsumerAfterDowngrade(t *testing.T) {
 	mset, err = s.globalAccount().lookupStream("DowngradeConsumerTest")
 	require_NoError(t, err)
 	require_True(t, mset.closed.Load())
-	require_Equal(t, mset.offlineReason, "stopped")
+	require_Equal(t, mset.offlineReason, "stopped - unsupported consumer \"DowngradeConsumerTest\"")
 
 	obs := mset.getPublicConsumers()
 	require_Len(t, len(obs), 1)