[louisgag]

If controlDict has functions

    ggiCheck3
    {
type ggiCheck;
phi phi;
functionObjectLibs ("libsampling.so");
    }

    ggiCheck4
    {
type ggiCheck;
phi meshPhi;
functionObjectLibs ("libsampling.so");
    }

and constant/polyMesh/boundary defines my "outsideSlider" before my "insideSlider"

then the meshPhi output goes very high (ex: 20%-60%) at the first iteration and on the second iteration I get a floating point error.

If meshPhi output is disabled and phi enabled then everything works fine even if insideSlider is defined after outsideSlider in the boundary file.