Problem making a condicional forecast in dynare 4.5.7

Hello, i'm trying to make a conditional forecast, with the command, conditional_paths in dynare 4.5.7, but when i condition only the fist period y get the following mistake:

Index in position 1 exceeds array bounds (must not exceed 1).

Error in imcforecast (line 285)
    forecasts.controlled_exo_variables.ci.(deblank(options_cond_fcst.controlled_varexo(i,:))) =
    [tmp(t1,:)' ,tmp(t2,:)' ]';
    

This mistake only appears when i try to condition in the first period, it work just fine with the second, third or whrn y do it with more than one periods.

This is the code that i`m using:

conditional_forecast_paths;
var rfr_obs;
periods 1;
values 0.001;
end;

conditional_forecast(parameter_set = posterior_mode, controlled_varexo = (sh_rfr),
replic = 3000);