This warning message means that the user account is not linked in the employee information. 
To fix, click the profile icon in the upper-right corner of the page, go to Administration -Employee Information - select the employee - click Edit - then go to Employee Setup
In User Account, type in the Username the same Username registered in the User Account. Once done, go to the last page or Employee Summary then click Save to save the changes made.
To check the user account, click the profile icon in the upper-right corner of the page, go to Administration - User Management - select the employee - click Edit
Check the registered username.
