Issue Summary

Configure workflow transition screen which having Assignee and Due date field.
While workflow transition, if user firstly set the value for the Due date field, Assignee field user picker does not list any users.
If user firstly select the assignee field, it shows user list properly.

Steps to Reproduce

1. Configure workflow transition screen which has assignee and due date fields
2. Popup that workflow transition screen
3. Select due date first
4. Try to set assignee field, the assignee field does not list any user

Expected Results

Assignee field should show users always if the user have browse user and groups permission

Actual Results

Assignee field does not list any user afer focusing other field in workflow transition screen

Workaround

Select Assignee field at first.