ERROR line item for assignees

Hi All,

I've been working in Anaplan Workflow, when it comes to hierarchy task I am facing with a challenge. I chose a line-item driven assignee method in the hierarchy

Task, but I was not able to assign the particular line item for assignees.

The error showing in the line item for assignees: "There are no valid line items. Configure the module or select another module." I have already created a module and has kept the line item to be a list formatted one, but it still shows error.

Please let me know your inputs.