Accounts :: Can't Log On Locally Anymore - Username Or Password Is Incorrect

I don't know what I'm doing wrong, it seems I can't login with a local account. When we install Windows 7, it create a local account with administrative privileges. Usually I name that account LocalAdmin.

I was trying to to the same with Windows 10. I created a local account with the Computer Management MMC Console, named it LocalAdmin and put it in Administrators group.

At the logon screen, I click on "Other user", I enter the username this way MachineNameLocalAdmin and the password.

Everytime Windows 10 throw the error : "The username or password is incorrect. Try again."

How come we can't log on locally anymore???!