diff --git a/w3c-visserver-api/src/vsscommandprocessor.cpp b/w3c-visserver-api/src/vsscommandprocessor.cpp
index 5fa0d8b..ca46b20 100644
--- a/w3c-visserver-api/src/vsscommandprocessor.cpp
+++ b/w3c-visserver-api/src/vsscommandprocessor.cpp
@@ -31,14 +31,28 @@
 
 using namespace std;
 
-string malFormedRequestResponse(uint32_t request_id, const string action) {
+string malFormedRequestResponse(uint32_t request_id, const string action, string message) {
   jsoncons::json answer;
   answer["action"] = action;
   answer["requestId"] = request_id;
   jsoncons::json error;
   error["number"] = 400;
-  error["reason"] = "Request malformed";
-  error["message"] = "Request malformed";
+  error["reason"] = "Bad Request";
+  error["message"] = message;
+  answer["error"] = error;
+  answer["timestamp"] = time(NULL);
+  stringstream ss;
+  ss << pretty_print(answer);
+  return ss.str();
+}
+
+string malFormedRequestResponse(string message) {
+  jsoncons::json answer;
+  jsoncons::json error;
+
+  error["number"] = 400;
+  error["reason"] = "Bad Request";
+  error["message"] = message;
   answer["error"] = error;
   answer["timestamp"] = time(NULL);
   stringstream ss;
@@ -326,66 +340,75 @@ string vsscommandprocessor::processQuery(string req_json,
                                          wschannel &channel) {
   jsoncons::json root;
   string response;
-  root = jsoncons::json::parse(req_json);
-  string action = root["action"].as<string>();
+  try {
+    root = jsoncons::json::parse(req_json);
+    string action = root["action"].as<string>();
 
-  if (action == "authorize") {
-    string token = root["tokens"].as<string>();
-    uint32_t request_id = root["requestId"].as<int>();
+    if (action == "authorize") {
+      string token = root["tokens"].as<string>();
+      uint32_t request_id = root["requestId"].as<int>();
 #ifdef DEBUG
-    cout << "vsscommandprocessor::processQuery: authorize query with token = "
-         << token << " with request id " << request_id << endl;
+      cout << "vsscommandprocessor::processQuery: authorize query with token = "
+           << token << " with request id " << request_id << endl;
 #endif
-    response = processAuthorize(channel, request_id, token);
-  } else if (action == "unsubscribe") {
-    uint32_t request_id = root["requestId"].as<int>();
-    uint32_t subscribeID = root["subscriptionId"].as<int>();
+      response = processAuthorize(channel, request_id, token);
+    } else if (action == "unsubscribe") {
+      uint32_t request_id = root["requestId"].as<int>();
+      uint32_t subscribeID = root["subscriptionId"].as<int>();
 #ifdef DEBUG
-    cout
-        << "vsscommandprocessor::processQuery: unsubscribe query  for sub ID = "
-        << subscribeID << " with request id " << request_id << endl;
+      cout << "vsscommandprocessor::processQuery: unsubscribe query  for sub "
+              "ID = "
+           << subscribeID << " with request id " << request_id << endl;
 #endif
-    response = processUnsubscribe(request_id, subscribeID);
-  } else {
-    string path = root["path"].as<string>();
-    uint32_t request_id = root["requestId"].as<int>();
+      response = processUnsubscribe(request_id, subscribeID);
+    } else {
+      string path = root["path"].as<string>();
+      uint32_t request_id = root["requestId"].as<int>();
 
-    if (action == "get") {
+      if (action == "get") {
 #ifdef DEBUG
-      cout << "vsscommandprocessor::processQuery: get query  for " << path
-           << " with request id " << request_id << endl;
+        cout << "vsscommandprocessor::processQuery: get query  for " << path
+             << " with request id " << request_id << endl;
 #endif
 
-      response = processGet(channel, request_id, path);
+        response = processGet(channel, request_id, path);
 #ifdef JSON_SIGNING_ON
-      response = signer->sign(response);
+        response = signer->sign(response);
 #endif
-    } else if (action == "set") {
-      jsoncons::json value = root["value"];
+      } else if (action == "set") {
+        jsoncons::json value = root["value"];
 #ifdef DEBUG
-      cout << "vsscommandprocessor::processQuery: set query  for " << path
-           << " with request id " << request_id << " value "
-           << pretty_print(value) << endl;
+        cout << "vsscommandprocessor::processQuery: set query  for " << path
+             << " with request id " << request_id << " value "
+             << pretty_print(value) << endl;
 #endif
-      response = processSet(channel, request_id, path, value);
-    } else if (action == "subscribe") {
+        response = processSet(channel, request_id, path, value);
+      } else if (action == "subscribe") {
 #ifdef DEBUG
-      cout << "vsscommandprocessor::processQuery: subscribe query  for " << path
-           << " with request id " << request_id << endl;
+        cout << "vsscommandprocessor::processQuery: subscribe query  for "
+             << path << " with request id " << request_id << endl;
 #endif
-      response =
-          processSubscribe(channel, request_id, path, channel.getConnID());
-    } else if (action == "getMetadata") {
+        response =
+            processSubscribe(channel, request_id, path, channel.getConnID());
+      } else if (action == "getMetadata") {
 #ifdef DEBUG
-      cout << "vsscommandprocessor::processQuery: metadata query  for " << path
-           << " with request id " << request_id << endl;
+        cout << "vsscommandprocessor::processQuery: metadata query  for "
+             << path << " with request id " << request_id << endl;
 #endif
-      response = processGetMetaData(request_id, path);
-    } else {
-      cout << "vsscommandprocessor::processQuery: Unknown action " << action
-           << endl;
+        response = processGetMetaData(request_id, path);
+      } else {
+        cout << "vsscommandprocessor::processQuery: Unknown action " << action
+             << endl;
+      }
     }
+  } catch (jsoncons::json_parse_exception e) {
+    return malFormedRequestResponse(e.what());
+  } catch (jsoncons::key_not_found e) {
+    return malFormedRequestResponse(e.what());
+  } catch (jsoncons::not_an_object e) {
+    return malFormedRequestResponse(e.what());
   }
 
+
   return response;
 }
diff --git a/w3c-visserver-api/src/vssdatabase.cpp b/w3c-visserver-api/src/vssdatabase.cpp
index 7fbf358..a68f0da 100644
--- a/w3c-visserver-api/src/vssdatabase.cpp
+++ b/w3c-visserver-api/src/vssdatabase.cpp
@@ -620,7 +620,7 @@ jsoncons::json vssdatabase::getSignal(class wschannel& channel, string path) {
     // check Read access here.
     if (!accessValidator->checkReadAccess(channel, jPath)) {
       stringstream msg;
-      msg << "No read access to  " << getReadablePath(jPath);
+      msg << "No read access to " << getReadablePath(jPath);
       throw noPermissionException(msg.str());
     }
     rwMutex.lock();
diff --git a/w3c-visserver-api/unit-test/w3cunittest.cpp b/w3c-visserver-api/unit-test/w3cunittest.cpp
index c7e7fb0..a55cc77 100755
--- a/w3c-visserver-api/unit-test/w3cunittest.cpp
+++ b/w3c-visserver-api/unit-test/w3cunittest.cpp
@@ -1779,7 +1779,7 @@ BOOST_AUTO_TEST_CASE(permission_basic_read_with_non_permitted_path, *utf::expect
 
    json expected = json::parse(R"({
                    "action":"get",
-                   "error":{"message":"No read access to  Vehicle.OBD.Speed","number":403,"reason":"Forbidden"},
+                   "error":{"message":"No read access to Vehicle.OBD.Speed","number":403,"reason":"Forbidden"},
                    "requestId":8756
         })");
 
@@ -1830,7 +1830,7 @@ BOOST_AUTO_TEST_CASE(permission_basic_read_with_invalid_permission_valid_path)
 
    json expected = json::parse(R"({
                    "action":"get",
-                   "error":{"message":"No read access to  Vehicle.OBD.EngineSpeed","number":403,"reason":"Forbidden"},
+                   "error":{"message":"No read access to Vehicle.OBD.EngineSpeed","number":403,"reason":"Forbidden"},
                    "requestId":8756
         })");
 
@@ -2040,7 +2040,7 @@ BOOST_AUTO_TEST_CASE(permission_basic_read_with_wildcard_write_permission)
 
    json expected = json::parse(R"({
                    "action":"get",
-                   "error":{"message":"No read access to  Vehicle.OBD.EngineSpeed","number":403,"reason":"Forbidden"},
+                   "error":{"message":"No read access to Vehicle.OBD.EngineSpeed","number":403,"reason":"Forbidden"},
                    "requestId":8756
         })");
 
@@ -2456,7 +2456,7 @@ BOOST_AUTO_TEST_CASE(permission_basic_write_with_branch_permission)
   // because only write access in the token.
   json get_expected = json::parse(R"({
     "action": "get",
-    "error":{"message":"No read access to  Vehicle.OBD.Speed","number":403,"reason":"Forbidden"},
+    "error":{"message":"No read access to Vehicle.OBD.Speed","number":403,"reason":"Forbidden"},
     "requestId": 8756
     })");