No value was entered in the SourceUsername field. If you are an administrator of this AD LDS instance, you can remove the ...

No value was entered in the SourceUsername field.  If you are an administrator of this AD LDS instance, you can remove the SourceUsername field from the unattended setup file. If you are not an administrator of this AD LDS instance, type the credentials for an account with administrative permissions for AD LDS in the SourceUsername and SourcePassword fields.  After you have updated the unattended setup file, run Setup again.