Character can't be too far outside the world center or the simulation falls apart.

[jarllarsson]

Possibly, the calculations(either in bullet or in the locomotion sim, or both) are too reliant on floating point precision to work with a certain parameter set outside the area in which it was generated (which is in the world center at the moment) or there is another bug somewhere in the locomotion sim which causes this.
Quick fix to allow for visualizations has been implemented as a render offset (m_positionOffset in the transform component), which is only used by the renderer.