Ah alright, I see. No - sorry if that somehow gave you the illusion that there would be a hidden option.
Thank you very much for your model. As I saw your “Block” already contains the transistor as well as the heatsink. What I have done now is:
Export only the block as an IGES file
Import into your workbench by selecting the file from your computer
Mesh the geometry
That should help getting rid of the non-positive Jacobian caused by zero or negative volume.
Please keep me up-to-date if that fixes your problems. If so, please also adapt the other models you have.