Matrix is singular to working precision problem

[jpfeifer]

It seems the fundamental problem is the same one as at

Perfect foresight simulation always failed

The problem is the equation Lam(1)*(R(1) + 1 - del) = 1; All variables here are dated t+1. Thus, in the last period, the derivative with respect to all variables will be 0. This is no problem for stochastic simulation. For deterministic ones, do not rely on auxiliary definitions. Use beta*C/C(+1)/G*(R(1) + 1 - del) = 1; and the file will work.

Have a look at the attached file where I reduced the crazy tolerance you set, increased periods and substituted in for the Lagrange multiplier.
Dynare_forum.mod (11.9 KB)