Hi Francois,
I was using the MNI ICBM152 template, which comes with one vertice outside the inner-skull surface, in fact, also the ICBM152_2016c template comes with same bug:
I just fix the vertice coordinates by hand, pushing it inside the inner-skull surface. Nevertheless, I think that better than fixing this template, which is also important, a control function could be added before to estimate the head model for a good leadfield estimation and time saving.
Thanks for your time and support.
All the Best,
Eduardo.