Index: dialin/ui/hd_simulator.py
===================================================================
diff -u -r0f182516739bda0dde1e69f62d31a107d154a3fc -r5dd18d4a2d618f399e4c29c6674266ba58ffb846
--- dialin/ui/hd_simulator.py	(.../hd_simulator.py)	(revision 0f182516739bda0dde1e69f62d31a107d154a3fc)
+++ dialin/ui/hd_simulator.py	(.../hd_simulator.py)	(revision 5dd18d4a2d618f399e4c29c6674266ba58ffb846)
@@ -1316,6 +1316,7 @@
 
         payload = float_to_bytearray(target)
         payload += float_to_bytearray(current)
+        payload += float_to_bytearray(0)
 
         message = DenaliMessage.build_message(channel_id=DenaliChannels.hd_to_ui_ch_id,
                                               message_id=MsgIds.MSG_ID_HD_BLOOD_PRIME_PROGRESS.value,