Error in solving dispersion relation for 2D Photonic Crystal

Hi,

I have been trying to compute band diagram for a 2D photonic crystal similar to the one described in the documentation for ver3.5. I have been working on v4.3a and when I click compute, I face the following error:

Undefined value found.
- Detail: Undefined value found in the stiffness matrix.
There are 537 equations giving NaN/Inf in the matrix rows for the variable mod1.E2z.
at coordinates: (-3.88906e-008,-5.82024e-008), (-4.43953e-008,-5.41208e-008), (-4.94979e-008,-4.9497e-008), (-5.41216e-008,-4.43942e-008), (-5.82032e-008,-3.88895e-008), ...
and similarly for the degrees of freedom, NaN/Inf in the matrix columns.

I am attaching my mph file along with this. Any help would be appreciated.

Thanks in advance,
Aman