See also How to create CIFS Share on Data domain and access CIFS Share from  Windows and Configuring a CIFS Share

Which user do you use and how are you doing it?

Use a standard user with administrator rights on the DD160. and that the user tries to go to the shared folder.

Hi.

You should specify both user and client name when defining a CIFS share.

Something like:

cifs share create share1 path /backup/share1 clients %ip_or_name_of_server% users %user_name%

You could replace the clients and user variable with * to make this an open share.