Niagara compile error : Select Position from Array

A similar node, Select Vector From Array, does not have this problem.
The difference between the two seems to be whether or not Required is checked in the input node's exposure options.

1. Create a new NiagaraSystem
2. When the NiagaraSystem wizard dialog appears, select "New system form selected emitters"
3. Select one of the emitters, click the + button, and then click the Finish button
4. Open the NiagaraSystem
5. Create a Position Array parameter in User Exposed
6. Create a Position parameter in System Attribute
7. Drag & Drop the Position parameter to the System Spawn slot of the NiagaraSystem
8. In the Selection pane, click pull-down button at the New Position parameter
9. Select "Select Position From Array"
10. Set the Position Array parameter to the Position Array attribute slot

[Link Removed]

Result: 

Compile error occurs : 

Required input Position Array was not bound and could not be automatically bound. - Node: Select Position from Array Pin: Position Array -  NewNiagaraSystem, System Spawn Script,