Variable vs steady state value


I am solving a dynare model. When I use the variable in the model it gives an error “Impossible to find the steady state.” However, when I substitute the steady-state value for the variable in the model, dynare solves it easily.
Is there a reason why “variable” results in impossible to find the steady-state, while substituting it with steady state value solves the model?


One reason may be that the use of the variable in that place allows for a unit root and therefore infinitely many steady states.

Thanks for your reply. Is there a way to make it have a unique steady state?

If the unit root is not a bug, then you need to modify your model accordingly.