Not 100% on this. And I assume your using the most recent version (appears to be 6.2a).
Before making any changes, be sure to backup your index.xml file in case the fix doesnt work you can revert back.
Not sure on the defensive target window though.
All I do is use default UI with a few additions. With the game having more devs, I am not sure if there will be any UI modifications. SO I am holding out until F2P before diving back into UI's.
Find the line labeled:
Code:
<!-- Window filename="VGUIEncounterDisplay.xml"/ -->
Replace it with:
Code:
<Window filename="VGUIEncounerDisplay.xml"/>
Then find:
Code:
<Window filename="myUI_NewHUDEncounterDisplay.xml"/>
Replace it with:
Code:
<!-- Window filename="myUI_NewHUDEncounterDisplay.xml"/ -->
The above will put the default Target window back.