An error about the matlab code example_acrobot.m

[ppap36]

Hello, When I ran the code example_acrobot.m, the system got the error as below:

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

Error in calc_f_disc (line 18)
tau_2 = in2(2,:);

Error in ilqr/rollout (line 142)
                next_state = self.f_(current_state,current_input,self.dt_,self.parameters_);

Error in ilqr/solve (line 66)
            [states,inputs] = self.rollout();

Error in example_acrobot (line 42)
[states,inputs,k_feedforward,K_feedback,final_cost] = ilqr_.solve();

I will be appreciate if you give me a hand

[YumengXiu]

Same here, looks like only the bouncing ball environment works.