weird error with annular basis

[nathan magnan]

Hello,

I'm trying to launch an IVP on the annulus basis, but I get the following error on the build_solver line:

File "/home/nathan/ENTER/envs/dedalus3/lib/python3.11/site-packages/dedalus/core_basis.py", line 2288, in _last_axis_component_ncc_matrix
    J = arg_basis.operator_matrix('Z', m, spintotal_arg, size=Nmat)
        ^^^^^^^^^^^^^^^^^^^^^^^^^
AttributeError: 'NoneType' object has no attribute 'operator_matrix'

I've never seen it before, so I don't know how to deal with it. I've looked at the archive and there was one post about it a few years ago, but no answer.

Thanks for your help !

PS: Also, I see in some of the posts that the boundary conditions can be a bit tricky with the annulus basis. If I'm working with a vectorial velocity u, what's the best way to impose ur = 0 at the boundaries ?