"Mesh contains Root bone as root but animation doesn't contain the root track"

Try RM Fix Tool Plugin for UE5 (fixes any root motion problems and let’s you change animation direction
RM Fix Tool in Code Plugins - UE Marketplace (unrealengine.com)
https://youtu.be/JbWckEC9jlk?feature=shared

I came to a similar problem, and I had a retargeted skeleton for the animation. While importing I was choosing my skeleton instead of the one associated with the animation, which was causing the issue. You should choose the skeleton the animation was associated with and then retarget that skeleton to yours. Hope this helps. :- )

I’m running into the same issue on the import with the mocap recording. I can’t retarget in Unreal since it fails on the import due to the root track problem. I’ve tried to export the file with Blender (include root on the export) which didn’t solve the issue. Which brought me to motionBuilder. Do I just rename the bones in motionBuilder to match the naming convention of UE? There’s a slight difference in hierarchy (spine and neck). Any pointers on the workflow would be greatly appreciated.