This issue occurs when the Welcome Email has not yet been sent to any affected employee(s).
To resolve the error:
Log in to Express Leave as an administrator user.
From the Company Admin, Manage Users menu, use the Search field to search the employee in question.
Click the green Send Welcome Email button from Actions column on the right hand side of the screen.
The user should receive the welcome email. Follow the instructions in the Welcome Email to create your password.
The message is also seen sometimes with existing employees. To resolve in this circumstance:
Log in to Express Leave as Administrator.
From the Company Admin, Manage Users menu, use the Search field to search the employee in question.
Delete the user.
Request that Attache Support reinstate the employee.