Error using optimization module

I tried to simulate a forced convective heat transfer problem: water flow through a heat sink. When I did stationary study with initial values of optimization parameters, it ran well. But if I ran optimization, the following error occurred:
Undefined variable.
- Variable: CFLCMP
- Geometry: geom1
- Domain: 2
Failed to evaluate variable.
- Variable: comp1.spf.locCFL
- Defined as: CFLCMP
Failed to evaluate expression.
- Expression: nojac(comp1.spf.time_step_inv/comp1.spf.locCFL)
Failed to evaluate expression.
- Expression: d(d((comp1.spf.rho*nojac(comp1.spf.time_step_inv/comp1.spf.locCFL)*(-(comp1.u-nojac(comp1.u))*test(comp1.u)-(comp1.v-nojac(comp1.v))*test(comp1.v)-(comp1.w-nojac(comp1.w))*test(comp1.w)))*(dvol),{test@3}),comp1.u)

Anyone got an idea how to shoot this?
Thanks in advance