Jacobian matrix with infinite or not real elements

Hi to everyone,
I am trying to run sum simulations of a log-linearized model on dynare but unfortunately I always get the same error message: “error: The Jacobian matrix evaluated at the steady state contains elements that are not real or are infinite”.
I attach a copy of the mod-file.
Is anyone able to give me the reason?
ppp.mod (1.54 KB)

Given your parametrization, your second expression

evaluates to a complex number.