[Paulo SPS]

Hi there,
I have a UDF that defines particle source terms in Fluent 17 using DEFINE_DPM_SOURCE with the pressure-based solver.
I need to get the mass flow into the cell containing the particle for this calculation.
I tried using F_FLUX but I keep getting a segmentation fault error, is the mass flow not stored for faces of cells?
The relevant code that causes the crash (if I remove the "f_flow = F_FLUX(f,f_t);" line it doesn't crash):

DEFINE_DPM_SOURCE(Source, c, t, S, strength, p)
{
    Thread*f_t;
    face_t f;
    int n;
    real f_flow;
    
    c_face_loop(c, t, n)
        {
            f = C_FACE(c,t,n);
            f_t = C_FACE_THREAD(c,t,n);
            f_flow = F_FLUX(f,f_t);
    }
}