Failed to evaluate variable Jacobian

Hi,
I'm trying to implement Lithium-ion battery 2D tutorial on a 3D structure. I followed all steps but COMSOL gives me this error:
Failed to evaluate variable Jacobian.
- Variable: comp1.liion.cs_surface
- Geometry: 1
- Domain: 6
Domain 6 is the separator between anode and cathode. Its thickness is 0.1mm.
I can't figure out what this error is about. I appreciate any advice.

Best,
Mohad