Perspective viewport Error

I'm having a display issue with the rhino5 perspective viewport. Basically i've traced it back to a single component. If its enabled, then it hides everything in the rhino perspective viewport. It appears to only be a few curves and points that are visible, any gh preview geometry does not show up either

When its disabled, perspective view objects are visible, but top and right view look wireframe.

I've tried new rhino files, copy paste script into new file, replaced component. restored default viewport views.