I have a Server 2012 R2 standard in a DMZ, NOT JOINED TO AD. I've opened up SMB port 139 so I can UNC into it and upload some files. I've disabled the builtin "Administrator" account as per my usual and created my own local account "Dude" and added to local administrators group.
UNC into the server \\servername\c$ only works if I use the builtin "Administrator" account - after enabling it of course. Attempts to use any other manually created local admin account fails.
I also have this same issue trying to use Symantec BESR for backups, it only works if i use the local builtin "Administrator" account.
Please advise and thank you.