I had same Issue, And I found why this happened.
The reason that you cannot find the “Ratio” things in context menu, that’s why you were not set the “Animation Sequence” in your state.
In your case, double click “JumpStart” State, and make connection with “Jump_Start” Animation Sequence.
And you can find the “ratio” thing in “Asset Player” Section.
This is old question, but I hope this can help the people who watch that Tutorial.
I think the Tutorial is very awesome… I love ue4 because of the perfect video tutorials…