Volumecentroid issue

I am runming Volumecentroid and getting this message complete with speling eror.

“At least one selected object has incompatible normal directions. See Help for aditional information.”

The help file provides no information on this. What is the issue?

The workaround seems to be to explode and join.

Was this an imported object?
If not, how was it created?

I think the message is accure. One or more of the surfaces was “flipped”. Exploding and Joining gave Rhino a chance to unify the surface normals.

It was a very complex object that created using many steps.

Hi John -

RH-73575 VolumeCentroid: Spelling error in error message

The “[ i ] Mass Properties” link from its help page provides that information.