thicknesses in runtime

[Urbem]

I want to change rope thikness in runtime. Like this:
path.thicknesses.data[_index] = 5f;

but in the game the rope is not updated. I try Update this functions, without result:
Rope.UpdateParticleProperties();
ropeMeshRenderer.UpdateRenderer(Rope);
solver.UpdateParameters();

How I can update Rope thicknesses in runtime?