To do this, open up the outliner and select the locator (which should be at the top of the character’s hierarchy chain). Except, we need to make sure the root bone doesn’t move for the duration of the anim. If we play the animation here, the rig moves as intended. Open up Maya (Or your choice of 3D modeling software) and import your FBX file. Mixamo doesn’t really export nicely with Unreal, so we need to do some tweaking. This is happening because there is animation info on the root bone, and in Unreal, the rig moves in relation to the root. If we jump into this new asset in Unreal and show bones (show->bone->all heirarchy), we can see that the pelvis doesn’t move at all. In the download settings, make sure to download without skin and leave all other options at their default. When you’re happy with the animation, hit the download button. Pick something you like and use the sliders to make adjustments. Once done, you’re free to explore Mixamo’s library of animation. Locate the file that we had exported and Mixamo will begin to process the file. Over in Mixamo, if you haven’t already, sign up for an account and you will be prompted to either upload a character or select from a premade one. Make sure to select the mesh and not the skeleton or physics component as we want to export both the mesh and its skeleton. LMB over the desired asset and click Asset Actions->Export. In this case, I will be using the standard Unreal model. Start out by opening your project in Unreal and selecting a mesh that you wish to add animations to. While the UE Marketplace has a nice collection of animation packs, I will show you how to use Mixamo (A currently free (as of 2017) rigging/animation toolkit) to import an already rigged character from Unreal and export animations provided by Mixamo. So you acquired some models from the unreal marketplace and want to spice it up with some animations. Step-by-step tutorial for adding animations provided by Mixamo to standard Unreal rigs

Mixamo download rigged model