No Subproblem error while using BallBasis

[Rainbow Star]

Hi, 

I am trying to solve inertial modes in full sphere using ball basis, where my NCC are dependent both on radius and latitude, I am getting this error (it was a testing script for a single m value), I am trying to solve Continuity, Navier-Stokes and Energy equation with one boundary condition (vanishing Lagrangian pressure perturbation at surface) and using integ(p_perturbation)=0, is this developmental threshold or I am missing something, I would be grateful for any suggestions or help.

2026-01-03 00:47:26,500 __main__ 0/1 INFO :: Building EVP solver...
2026-01-03 00:47:26,503 __main__ 0/1 INFO :: ======================================================================
2026-01-03 00:47:26,503 __main__ 0/1 INFO :: EVP Problem Built Successfully!
2026-01-03 00:47:26,503 __main__ 0/1 INFO :: ======================================================================
2026-01-03 00:47:26,503 __main__ 0/1 INFO :: Total subproblems: 1
2026-01-03 00:47:26,503 __main__ 0/1 INFO :: Available subproblem groups:
2026-01-03 00:47:26,503 __main__ 0/1 INFO ::   (None, None, None)
2026-01-03 00:47:26,503 __main__ 0/1 INFO :: Using coupled subproblem (None, None, None) - all azimuthal modes included
2026-01-03 00:47:26,503 __main__ 0/1 INFO :: Building matrices for subproblem...
2026-01-03 00:47:26,656 __main__ 0/1 ERROR ::   Failed to build matrices: bad operand type for abs(): 'NoneType'
2026-01-03 00:47:26,656 __main__ 0/1 ERROR :: Error during solve: bad operand type for abs(): 'NoneType'