KeyError(3,3) when running objective function

xc_origin = np.array([0])             # x-cordinate for the port of origin defined as an array
xc_destination = np.array([10])       # x-cordinate for the port of destination defined as an array
xc_hub = np.array([5])                # x-cordinate for the fuel hub defined as an array

yc_origin = np.array([5])             # y-cordinate for the port of origin defined as an array
yc_destination = np.array([5])        # y-cordinate for the port of destination defined as an array
yc_hub = np.array([0])                # y-cordinate for the fuel hub defined as an array

num_points_network = 27               # Defining numer of points we wish to generate between the two ports and the fuel hub. This value are arbitrarly

generate_random_cordinates = True     # if True we genrate random network of points between the ports and hub(s) (Realistic scenario)

if generate_random_cordinates:
    xc_random = np.random.randint(low=np.min(xc_origin)+1, high=np.max(xc_destination)-1, size=num_points_network)  # generating random values for the locations between the two x cordinates for the ports
    if len(yc_hub) <= 2:
        y_pot_hub_max =10
    else:
        y_pot_hub_max = np.max(yc_hub)-1

    yc_random = np.random.randint(low = np.min(yc_hub)+1, high = y_pot_hub_max, size=num_points_network)           # generating random values for the locations between the two y cordinates for the hubs

                                      
                                      
                                      
xc = np.concatenate((xc_origin, xc_destination, xc_hub, xc_random), axis=0) # adding all x-cordinate arrays together
yc = np.concatenate((yc_origin, yc_destination, yc_hub, yc_random), axis=0) # adding all y-cordinate arrays together  

origin_index = [int(i) for i in range(len(xc_origin))]
destination_index = [int(i+len(xc_origin)) for i in range(len(xc_destination))]
hub_index = [int(i+len(xc_origin)+len(xc_destination))for i in range(len(xc_hub))]
random_index = [int(i+len(xc_origin)+len(xc_destination)+len(xc_hub)) for i in range(len(xc_random))]

P = origin_index + destination_index          # Index position for Location of port of Origin, O and port of destination, D
H = hub_index                                 # Index position for energy hub
L = random_index                              # Index position for replenishment locations
N = P+H+L                                     # Defining all possible nodes (replenishment locations)
V = [0]                                       # Initial position of vessel

C_S = 1 # Cost of sailing from node  𝑖 to 𝑗 [$/𝑛𝑚]
C_LOC = 4 # Lost opportunity cost per unit energy storage capacity  [$/𝑚3]
K_V = 10  # Total storage capacity of vessel  [𝑚3]
E_V =  1  # Energy consumption per distance traveled  [𝑚3/𝑛𝑚]
C_FHS = 1 # Cost of supplying fuel from a fuel hub per distance unit  [$/𝑛𝑚]
C_FHE = 1   # Fixed cost of establishing an energy replenishment location

A = [(i,j) for i in N for j in N if i!=j] # defining all possible arcs
D_ij = {(i,j): np.hypot(xc[i]-xc[j],yc[i]-yc[j]) for i,j in A} # Sailing distance between node  𝑖 and node 𝑗 [𝑛𝑚] 

mdl = Model("Optimal location of energy replenishment for a network of locations")

x_ij = mdl.addVars(A, vtype = GRB.BINARY)        # If veseel 𝑣 visits the enrgy replenishment station $j$, 0 otherwise
k_ES = mdl.addVar(vtype = GRB.CONTINUOUS)        # Energy storage capacity of the vessel
e_ij = mdl.addVars(A, vtype = GRB.CONTINUOUS)    # energy consumption for the vessel from node  𝑖 to to node 𝑗

# Objective function

mdl.modelSense = GRB.MINIMIZE
mdl.setObjective(quicksum(C_S * D_ij[i,j] * x_ij[i,j] + C_LOC * k_ES for i,j in A) 
                + quicksum((C_FHS * D_ij[hub_index[0],j] + C_FHE) * x_ij[i,j] for i in N for j in L if j != H))

    

When i run the code above i get the following error:

KeyError(3,3)

The error seems to occur in the objective function.

How can I resolve the issue?

Any help would be appreciated