For users in whose machine drag-drop between AI and Design Library is not working, can they please try following:
1) Open Terminal app on your mac and run this command:
/System/Library/Frameworks/CoreServices.framework/Versions/A/Frameworks/LaunchServices.fra mework/Versions/A/Support/lsregister –dump > ~/Desktop/dump.txt
Send this dump.txt to ShareWithAI@adobe.com mentioning your user id in the subject of the mail.
2) Run the command:
/System/Library/Frameworks/CoreServices.framework/Versions/A/Frameworks/LaunchServices.fra mework/Versions/A/Support/lsregister -f "/Applications/Adobe Illustrator CC 2014/Adobe Illustrator.app"
The 2nd step might help you fix the drag-drop problem. Please do post your findings here that whether drag-drop started working for you or not.
Thanks and Regards
Ankit Aggarwal (Adobe Illustrator Staff)