Hello again

I m trying to simulate a force applied on the flange_b of one body.
I have connected the flange b of the force with the point i want it to be applied and i have chosen the force to be resolved in world frame.
I created a constant input of i.e. {100, 100, 100} nt but when i try to connect the constant block to the input of the force i get the following message pops up

"Connect Array:Connect constant.y with force.force[index], Enter index value for force.force"
if i leave the pop up box  blank an error message appeas saying "Enter a valid positive integer index value for force.force"
In the box i am only allowed to type numbers....nothing else

What i m i supposed to fill in the pop up box?