Hi ,
I was able to reproduce this behavior. It seems duplicating a Timeline in MyBlueprint tab only creates a variable of same type with same tooltip, but it doesn’t actually function as a Timeline and it cannot be renamed. Interestingly, even attempting to do duplicate a Timeline this way will crash 4.6.1. I have entered a bug report for developers (UE-7392) and will let you know when I see an update. Thanks for report!