some problems about cantilever under Electrostatic force + contact

Hi,

When I simulate cantilever bending under electrostatic force with COMSOL, there are some problems and errors I can not fix. Could someone please give me advises? I attach my file.
(1) When the applied voltage is larger than pull in, the cantilever should crash to the substrate. Right now when I apply voltage bigger than pull-in, there is error 'Failed to find a solution: In segregated group 1: Divergence of the linear iterations. Returned solution has not converged.' and warning 'inverted mesh element near ...' .

What to do with this error and warning?

(2) The contact pairs I set up are the bottom of cantilever and the top of glass. Does it matter that which is source and which is destination? What to do with the penalty factor and contact pressure?

(3) I follow "ale_cantilever_beam_2d.mph" to set up the multiphysics relation between solid mechanics and electrostatic by integrating Q. However I am not sure whether I did the right multiphysics set, since the example is from 3.5a version which is quite different from 4.0.

Thanks a lot!