Symptoms

Customers may say:

The retargeted clip stays in a T-pose or barely moves.
The feet slide, drift, or lose contact.
The clip plays but the character does not travel the way they expected.
The hips, pelvis, or root behave unpredictably after retargeting.

Quick Answer

Most Unreal retargeting failures come from one of four causes: the chain mapping is wrong, the source and target poses do not match, the retarget root or pelvis setup is incomplete, or the clip's movement behavior was misunderstood before retargeting started.

Before You Start

Confirm:

Product or pack: the exact MoCap Online pack shown in your order, download, or product page.
Format used: Unreal Engine pack, FBX Format, or All Formats if your download includes multiple format folders.
Unreal version: Unreal Engine 5 for this guide; source note below is verified against Unreal Engine 5.7.
Source skeleton and target skeleton: the skeleton used by the MoCap Online source animations and the skeleton used by your project character.
Whether the source clip already contains authored travel or is effectively in-place.

Fix Path 1 - The character T-poses or barely animates

Re-open the retarget asset and confirm the source and target chains are mapped to the intended limbs.
Make sure the source preview animation actually plays on the source skeleton before you judge the retarget result.
Re-check the source and target retarget poses. If one character starts from a different reference pose, correct that mismatch before exporting again.

Fix Path 2 - The feet slide or contact looks wrong

Confirm that the retarget pose is not twisting the legs or feet before the animation even starts.
If the project needs stronger contact stability, review the current Unreal retarget workflow for optional IK goals and Speed Planting.
Re-preview the clip after each change instead of exporting full batches blindly.

Fix Path 3 - The clip plays but the character does not travel correctly

First decide whether the source clip actually contains travel or whether it is an in-place clip.
If the source clip is in-place, retargeting alone will not magically turn it into a reliable authored-travel clip.
If the source clip does contain travel, make sure Set Retarget Root was defined on both rigs before retargeting.
After export, review the animation asset's root-motion settings in Animation Sequence Editor > Asset Details > EnableRootMotion.
If needed, also review Root Motion Root Lock, Force Root Lock, and Use Normalized Root Motion Scale.

Fix Path 4 - Pelvis, hips, or root look unstable

Re-check which bone was chosen with Set Retarget Root on both rigs.
Make sure the main spine and leg chains start and end on the intended bones.
Compare source and target retarget poses again, because a bad base pose often shows up as pelvis drift or body lean.

If That Does Not Work

Collect:

one short video or screenshot of the retarget preview
the exact Unreal Engine 5 minor version used in the project
the source skeleton name and target skeleton name from your project
whether the source clip is root-motion or in-place
the specific symptom: T-pose, sliding, no travel, pelvis instability, or something else

Escalate for technical review if the source skeleton name conflicts with the expected MoCap Online format, if the target skeleton is custom or heavily modified, or if root-motion behavior depends on gameplay code outside the animation asset.

Source notes for review

Verified against Unreal Engine 5.7 documentation, May 2026.
Product-format source checked against MCO - Products FORMAT records for Unreal Engine, FBX Format, and All Formats, plus Canonical Product Map format availability fields.
Exact source and target skeleton names are project-specific. The public guidance asks customers to collect those names instead of hard-coding one skeleton label into the article.

Unreal Engine 5 retargeting and root-motion troubleshooting