We investigated a situation where an SMB client could not connect to an SMB server. The SMB server returned an “Access Denied” during the NTLM authentication.
If a user attempts to connect to a mapped drive or folder they don't have permissions for, it asks for network credentials instead of just saying access denied.
I simply have not been able to access any share from this one WIn2012 R2 server, it's a Domain controller.. I AM trying in the correct username and password.