Index: scripts/MsgUtils/msgutils/templates/MsgProtoUtils_cpp.jinja
===================================================================
diff -u -r59b4c22f45a1d098064a886452769204e90cfb4b -raaebfee335c74b0250864a6dce0555f866adadea
--- scripts/MsgUtils/msgutils/templates/MsgProtoUtils_cpp.jinja	(.../MsgProtoUtils_cpp.jinja)	(revision 59b4c22f45a1d098064a886452769204e90cfb4b)
+++ scripts/MsgUtils/msgutils/templates/MsgProtoUtils_cpp.jinja	(.../MsgProtoUtils_cpp.jinja)	(revision aaebfee335c74b0250864a6dce0555f866adadea)
@@ -12,18 +12,17 @@
 {%- endif %}
 
 // Populate the protobuf Header (field 1) shared by every typed message.
-static void updateHeader(messages::Header *header, const QDateTime &timestamp, const QString &deviceSerialNum, quint16 msgId, qint16 sequence)
+static void updateHeader(messages::Header *header, const QDateTime &timestamp, qint16 sequence, quint16 msgId)
 {
     if (header) {
         const auto msecs = timestamp.toMSecsSinceEpoch();
-        header->set_deviceserialnum(deviceSerialNum.toStdString());
         auto proto_timestamp = header->mutable_timestamp();
         if (proto_timestamp) {
             proto_timestamp->set_seconds(msecs / 1000);
             proto_timestamp->set_nanos((msecs % 1000) * 1000000);
         }
-        header->set_msgid(msgId);
         header->set_sequence(sequence);
+        header->set_msgid(msgId);
     }
 }
 {%- for (msg_id_value, msg) in msg_cpp.data.items() %}
@@ -32,12 +31,13 @@
 // {{ msg['msg_id'] }} ({{ msg['msg_id_hex_string'] }})
 // payload: {{ msg_cpp.field_list(msg_id_value) | join(", ") }}
 // serializeProto: msg struct -> QByteArray of serialized protobuf data (header populated from params)
-QByteArray serializeProto([[maybe_unused]] const {{ msg['msg_name'] }}Payload &src, const QDateTime &timestamp, const QString &deviceSerialNum, quint16 msgId, qint16 sequence)
+bool serializeProto([[maybe_unused]] const {{ msg['msg_name'] }}Payload &src, const QDateTime &timestamp, qint16 sequence, quint16 msgId, QByteArray &dst)
 {
 {%-     if has_union %}
     qDebug().noquote() << "WARNING: MsgId={{ msg['msg_name'] }} contains union/oneof field(s); protobuf serialization is partial";
 {%-     endif %}
     messages::{{ msg['msg_name'] }} proto;
+    updateHeader(proto.mutable_header(), timestamp, sequence, msgId);
 {%-     for field in msg['payload'] %}
 {%-         if field['type'] != "union" %}
     // {{ field['type'] ~ "-" ~ field['name'] }}
@@ -46,10 +46,15 @@
     // TODO: {{ field['type'] ~ "-" ~ field['name'] }}
 {%-         endif %}
 {%-     endfor %}
-    updateHeader(proto.mutable_header(), timestamp, deviceSerialNum, msgId, sequence);
     std::string out;
-    (void)proto.SerializeToString(&out);
-    return QByteArray(out.data(), static_cast<int>(out.size()));
+    if (proto.SerializeToString(&out)) {
+        dst = QByteArray::fromStdString(out);
+        return true;
+    }
+    else {
+        dst = QByteArray();
+        return false;
+    }
 }
 
 // {{ msg['msg_id'] }} ({{ msg['msg_id_hex_string'] }})
@@ -61,39 +66,44 @@
     qDebug().noquote() << "WARNING: MsgId={{ msg['msg_name'] }} contains union/oneof field(s); protobuf deserialization is partial";
 {%-     endif %}
     messages::{{ msg['msg_name'] }} proto;
-    if (proto.ParseFromArray(bytes.constData(), bytes.size()) == false) {
-        qDebug().noquote() << "ERROR: could not parse protobuf for MsgId={{ msg['msg_name'] }}";
-        return false;
-    }
+    if (proto.ParseFromArray(bytes.constData(), bytes.size())) {
 {%-     for field in msg['payload'] %}
 {%-         if field['type'] != "union" %}
-    // {{ field['type'] ~ "-" ~ field['name'] }}
-    dst.{{ field['name'] }}.value = proto.{{ field['name'].lower() }}();
+        // {{ field['type'] ~ "-" ~ field['name'] }}
+        dst.{{ field['name'] }}.value = proto.{{ field['name'].lower() }}();
 {%-         else %}
-    // TODO: {{ field['type'] ~ "-" ~ field['name'] }}
+        // TODO: {{ field['type'] ~ "-" ~ field['name'] }}
 {%-         endif %}
 {%-     endfor %}
-    return true;
+        return true;
+    }
+    else {
+        return false;
+    }
 }
 {%- endfor %}
 
-QByteArray canMessageToProtobufByteArray(const QDateTime &timestamp, const QString &deviceSerialNum, const Can::Message &msg)
+bool canMessageToProtobufByteArray(const QDateTime &timestamp, const Can::Message &msg, QByteArray &dst)
 {
     switch (msg.msgId) {
 {%- for (msg_id_value, msg) in msg_cpp.data.items() %}
         case {{ msg['msg_id'] }}: {
             {{ msg['msg_name'] }}Payload payload;
-            if (payload.fromQByteArray(msg.data) == false) {
-                qDebug().noquote() << "ERROR: could not convert CAN message with MsgId={{ msg['msg_name'] }} to struct";
+            if (payload.fromQByteArray(msg.data)) {
+                return serializeProto(payload, timestamp,  msg.sequence, msg.msgId, dst);
             }
-            return serializeProto(payload, timestamp, deviceSerialNum, msg.msgId, msg.sequence);
+            else {
+                dst = QByteArray();
+                return false;
+            }
         }
 {%- endfor %}
         default:
             qDebug().noquote() << QString("WARNING: MsgId=0x%1 not handled").arg(msg.msgId, 4, 16, QChar('0'));
+            dst = QByteArray();
+            return false;
             break;
     }
-    return QByteArray();
 }
 
 // Maps a msgId to its fully-qualified protobuf message name for descriptor-pool lookup.