Comsol 4.3 with Matlab - ACDC Rotating machinery - Identity Pair

Hi Comsol forum,

this is the very first time I open a new thread.
I want to share (and I hope to solve) the problem which is afflicting me when I try to run a time dependent problem using Matlab 2012.

I am performing a 2D geometry optimization on a small permanent magnet synchronous motor: I followed the guide in the geometry declaration (especially the identity pair in the middle air gap surface between stator and rotor unions and the continuity along the surface).

I managed to perform both stationary and time dependent simulation, everything seems ok
BUT

when I launch the simulation with matlab I encountered the a problem:

the following strings



model.pair.name('List');

model.pair('ap4').name('Identity Pair 4');

model.physics('rmm').feature('cont1').set('pairs', 'ap4');


cause an error called something like "java error"
Since I do not know Java I wondered if anybody could help me.

Thanks in advance,
Andrea