diff --git a/qgroundcontrol.pro b/qgroundcontrol.pro
index dc53378a7662999d3014b512f5c5952d7288cfbe..1b5dd47a7234844fa98f4510817e546610999ad1 100644
--- a/qgroundcontrol.pro
+++ b/qgroundcontrol.pro
@@ -129,28 +129,47 @@ WindowsBuild {
 }
 
 #
-# We treat all warnings as errors which must be fixed before proceeding. If you run into a problem you can't fix
-# you can always use local pragmas to work around the warning. This should be used sparingly and only in cases where
-# the problem absolultey can't be fixed.
+# We treat all warnings as errors which must be fixed before pull requests are approved. If you run into a problem 
+# you can't fix you can always use local pragmas to work around the warning. This should be used sparingly and only 
+# in cases where the problem absolultey can't be fixed.
 #
+# If you run into problems in code which is not yours, please lend a hand and fix the issues. If you don't have time
+# for that post an Issue with your OS and compiler information as well as the pertinent output from the build log. If it's
+# a problem that will take longer to fix, we will temporarily turn off warnings as errors for that specific config until
+# the Issue is taken care of. Once that is completed we will turn warnings as errors back in for the config. You can use
+# CONFIG+=WarningsAsErrorsOff in your private builds for a quick local override.
+#
+# Please report any problems you run into with warnings as errors so we can gather information on its effectiveness as well
+# as its annoyance level.
+#
+
+# Note: -Werror is currently not turned on for Linux due to unfixed problems with release builds. See Issue 535. This will 
+# be removed once the Issue is taken care of.
+
+LinuxBuild {
+    CONFIG += WarningsAsErrorsOff
+}
 
 MacBuild | LinuxBuild {
 	QMAKE_CXXFLAGS_WARN_ON += -Wall
 }
 
-# Note: -Werror is currently not turned on for Linux due to unfixed problems with release builds
-
-MacBuild {
-	QMAKE_CXXFLAGS_WARN_ON += -Werror
+MacBuild | LinuxBuild {
+    !WarningsAsErrorsOff {
+        QMAKE_CXXFLAGS_WARN_ON += -Werror
+    }
 }
 
 WindowsBuild {
 	QMAKE_CXXFLAGS_WARN_ON += /W3 \
-        /WX \
         /wd4996 \   # silence warnings about deprecated strcpy and whatnot
         /wd4290     # ignore exception specifications
 }
 
+WindowsBuild : !WarningsAsErrorsOff {
+	QMAKE_CXXFLAGS_WARN_ON += /WX
+}
+
 #
 # Build flavor specific settings
 #
diff --git a/src/comm/MAVLinkSimulationMAV.cc b/src/comm/MAVLinkSimulationMAV.cc
index c414633e32b5ef7cd6d957b6b00a7771dc4bbd35..51e2669b84e5a4b325e71a7a9d40d6fde5895238 100644
--- a/src/comm/MAVLinkSimulationMAV.cc
+++ b/src/comm/MAVLinkSimulationMAV.cc
@@ -86,6 +86,7 @@ void MAVLinkSimulationMAV::mainloop()
         servos.servo6_raw = 1500;
         servos.servo7_raw = 1500;
         servos.servo8_raw = 2000;
+        servos.port = 1;    // set a fake port number
 
         mavlink_msg_servo_output_raw_encode(systemid, MAV_COMP_ID_IMU, &msg, &servos);
         link->sendMAVLinkMessage(&msg);
@@ -164,15 +165,30 @@ void MAVLinkSimulationMAV::mainloop()
 
         mavlink_msg_attitude_encode(systemid, MAV_COMP_ID_IMU, &msg, &attitude);
         link->sendMAVLinkMessage(&msg);
-
+        
         // SYSTEM STATUS
         mavlink_sys_status_t status;
+        
+        // Since the simulation outputs global position, attitude and raw pressure we specify that the
+        // sensors that would be collecting this information are present, enabled and healthy.
+        
+        status.onboard_control_sensors_present = MAV_SYS_STATUS_SENSOR_3D_GYRO |
+                                                    MAV_SYS_STATUS_SENSOR_3D_ACCEL |
+                                                    MAV_SYS_STATUS_SENSOR_3D_MAG |
+                                                    MAV_SYS_STATUS_SENSOR_ABSOLUTE_PRESSURE |
+                                                    MAV_SYS_STATUS_SENSOR_GPS;
+        
+        status.onboard_control_sensors_enabled = status.onboard_control_sensors_present;
+        status.onboard_control_sensors_health = status.onboard_control_sensors_present;
         status.load = 300;
-        //        status.mode = sys_mode;
-        //        status.nav_mode = nav_mode;
-        status.errors_comm = 0;
         status.voltage_battery = 10500;
-        //        status.status = sys_state;
+        status.current_battery = -1;  // -1: autopilot does not measure the current
+        status.drop_rate_comm = 0;
+        status.errors_comm = 0;
+        status.errors_count1 = 0;
+        status.errors_count2 = 0;
+        status.errors_count3 = 0;
+        status.errors_count4 = 0;
         status.battery_remaining = 90;
         mavlink_msg_sys_status_encode(systemid, MAV_COMP_ID_IMU, &msg, &status);
         link->sendMAVLinkMessage(&msg);
@@ -225,6 +241,13 @@ void MAVLinkSimulationMAV::mainloop()
             hil.pitch_elevator = 0.05f;
             hil.yaw_rudder = 0.05f;
             hil.throttle = 0.6f;
+            hil.aux1 = 0.0f;
+            hil.aux2 = 0.0f;
+            hil.aux3 = 0.0f;
+            hil.aux4 = 0.0f;
+            hil.mode = MAV_MODE_FLAG_HIL_ENABLED;
+            hil.nav_mode = 0;   // not currently used by any HIL consumers
+            
             // Encode the data (adding header and checksums, etc.)
             mavlink_msg_hil_controls_encode(systemid, MAV_COMP_ID_IMU, &ret, &hil);
             // And send it