MBL won't accept ANY username/password


I just bought a 2TB MBL, and updated to the latest firmware. I have created two users aside from the admin account - one with a password, one without. If I try to access the MBL from any of the Windows machines in my office, it prompts for a username/password - but it won’t work with either account. It just keeps prompting for username and password over and over and over. I’m positive nothing was mis-typed, I reviewed everything. I can’t even use the account that has no password - which makes no sense. And I was positive to type the account name with the exact capitalization I used to create the account (which is no capitals at all).

Has anyone else had this problem? Is there a fix? The MBL is pretty useless if we can’t access it, this is my last resort before returning it to the store.