When I add the Infinity Blade Warriors marketplace content pack to a 4.12 project there are no animations for the warriors. When I add the same pack to a 4.9 project the animations are there and work fine. It looks like the skeleton changed?
Here is how I fixed this issue in 4.12:
Go to the InfinityBladeWarriors/Character/CompleteCharacters folder and delete the SK_Mannequin Skeleton. Since there are Skeletal Meshes that are referencing this skeleton you are given the ability to replace it. Choose the UE4_Mannequin_Skeleton. Now open any of the Skeletal Meshes back up and the standard UE4 third person animations are now available for use.
It seems like maybe the marketplace content needs to be updated to work with 4.12.
Your solution works with 4.18 too. Thanks!
Works on 4.20 too but the mannequin skeleton wasn’t created to the same mesh proportions, so some parts go to weird positions. But it worked.