Error message after compute, modeling CFD of equipment in tunnel, advice? [CM 4.4]

Hi, I'm a very very beginner in using COMSOL Multiphysics 4.4, I've never used it before, but I've done some tutorials from the installer.

Now I'm trying to compute this model (can be seen attached, "model.jpg"), studying about air flow flowing through this equipment in a tunnel.

But, I don't know why, I got this message error after choosing the "compute" command (the error message is also attached, "comsol_error.jpg"):

Failed to evaluate operator.
- Operator: mean
- Geometry: 1
- Boundary: 2 3 4 5 142
Mean operator requires an adjacent entity of higher dimension.
Failed to evaluate expression.
- Expression: mean(comp1.spf.C_mu)
Failed to evaluate variable.
- Variable: comp1.spf.C_mu
- Geometry: 1
- Boundary: 2 3 4 5 142
Failed to evaluate expression.
- Expression: nojac(max(11.06,((((0.5*(comp1.spf.C_mu^0.25))*sqrt(max(comp1.k,0)))*down(comp1.spf.rho))/(down(comp1.spf.mu)*(down(tremetric)^0.5)))))
Failed to evaluate variable.
- Variable: comp1.spf.d_w_plus
- Defined as: nojac(max(11.06,((((0.5*(comp1.spf.C_mu^0.25))*sqrt(max(comp1.k,0)))*down(comp1.spf.rho))/(down(comp1.spf.mu)*(down(tremetric)^0.5)))))
Failed to evaluate temporary symbolic derivative variable.
- Variable: comp1.spf.ep_w@VDN$comp1.k
- Defined as: ((1/((comp1.spf.d_w_plus*comp1.spf.kappav)*nojac(down(comp1.spf.mu))))*(nojac(down(comp1.spf.rho))*(comp1.spf.C_mu*((2*max(comp1.k,0))*(comp1.k>0)))))
Failed to evaluate expression.
- Expression: d(-comp1.ep+comp1.spf.ep_w,comp1.k)

Do you have any idea on why did this happen? How to solve this problem?
I will be grateful for any help/opinion you can provide.
Cheers.