When you edit or make a change to one of the following User Roles in the SBS Console: "Network Administrator" or "Standard User with administration links" you get the following warning upon clicking OK or APPLY (example provided for Network Administrator role): Do you want to change the user name for network admin? if you change the username, problems can occur if the folders for this user account are redirected to the server, more information. If you’re editing one of the two Roles mentioned before and you get this warning, you can ignore this message and click yes to continue. We recommend that instead of editing the default roles provides, you create your own role and apply it to the users as needed, see for more details on User Roles.
Source:→ SBS Blog