Default [Q] Can not update S4 I9506 with 4.3 Firmware

I am trying to flash 4.3 firmware onto my S4 using odin but get the following error, any ideas? I have the de bugger selected, all drivers installed as far as I am aware of?

<OSM> Enter CS for MD5..
<OSM> Check MD5.. Do not unplug the cable..
<OSM> Please wait..
<OSM> 5 is valid.
<OSM> Checking MD5 finished Sucessfully..
<OSM> Leave CS..
<ID:0/005> Added!!
<ID:0/005> Odin v.3 engine (ID:5)..
<ID:0/005> File analysis..
<ID:0/005> SetupConnection..
<ID:0/005> Complete(Write) operation failed.
<OSM> All threads completed. (succeed 0 / failed 1