Trying to Retarget animations

Hi, i’m trying to retaget an animation from one character to another. I did so and it worked but then i had to update the skin weighting in maya for him since there were some issues with it. So i saved it out as a different name and reimpoted it into unreal. I then right clicked on the original animation> Retarget Anim Assets> Duplicate Anim Assets and Retarget … However when i went to click on the new skeleton from the list on the left , when I clicked on it nothing would show up in the Target window on the right, any ideas why? I have attached screenshots of what im seeing.

Thanks,
Dan