Calibrating with 3DCal

Wondering what I’m doing wrong to cause 3dCal to go blank?
I’ve now tried a number of times and the same happens each time.
I put six points on the projected object fine and then get as far as putting 5 or so points on the virtual object and then all of a sudden the 3dCal window goes blank - so I can no longer see the object. If Calibration On Change is not enabled, not surprisingly, I can get through the entire process but then when I hit Calibrate I get the blank screens. My selected dots are still there but no image.
Thanks

Hi,

This probably means the projector was moved to some point way off. This usually happens when the calibration points are not good - either they are coplanar or they are symmetrical. Please try selecting a different selection of points and observe where the projector is in the Visualizer window.

I hope this helps,
Mitja