Thanks for the prompt reply Lilybiri!
I closed captivate and deleted the "Interactions_10_0" in Public Documents\Adobe\eLearing Assets. Note: I have only captivate 2017 and no other previous version. When I open captivate the "Interactions_10_0" folder gets automatically created with the same two youtube widgets included namely "Youtube.wdgt" and "YoutubeFix.wdgt". I dont understand whats going wrong here. 
This means even the original folder Interactions in the installation folder of Captivate has both widgets. I ddin't check, sorry. If you want to get rid of one of them, please use the other approach
I checked: the Youtube is dated 6/4/2017, whereas the YoutubeFix is pretty recent: 18/3/2017. If you don't like to have them both, delete the first one. There were issues with that widget.