I seem to have uncovered a problem but perhaps it's unique.
Cause
Use the utility to generate support for a model. After the supports are created, rotate the model 180degrees in the Z axis. Everything seems OK and the supports rotate with the model as expected.
Symptom
After the rotation, the model will no longer slice, it just hangs. Removing the supports and regenerating them resolves this.
Resolution
Assuming that this is a bug, I think that either the application should recalculate the supports or remove them (ideally the former)
This is version 4.0.1