model_diagnostics says
MODEL_DIAGNOSTICS: The Jacobian of the static model is singular
MODEL_DIAGNOSTICS: there is 1 colinear relationships between the variables and the equations
Colinear variables:
N
Ns
Nu
No
Colinear equations
8 9 10 11 14 17 18 23
so you should find out what is going on there. Check all equations, including the timing. For example,
ks(-1) = Ns*((1 - delt)*ks(-1) + xs)/Ns(1);
looks wrong.