Unpolarized light

Hello,
I am trying to shine not polarized light on my structure, but I don't know how. I tried to do like if I polarized light but with no magnetic field. Meaning that took what is on the Fresnel equations model and change the field to zero but is gives me the following error:
Undefined value found
-Detail: Undefined value found in the constraint residual vector: NaN or Inf in vector

Please, can someone help me?

Have a great day,

Phil