Missing ‘+’ sign to create new Ship to Address using other roles aside from administrator role.

Setup > Users/Roles > Manage roles:

1.    Log in using a role other than an Administrator. Example, Customer Service Manager Role.

2.    Navigate to Customers > Sales Order > New > given that you don't see the 'plus' button in the Shipping tab.

3.    Log out and log back in using Administrator Role.

4.    Navigate to Setup > Users/Roles > Manage roles.

5.    Edit a role. Example, Customer Service Manager Role.

6.    Go to Permissions tab > Transactions sub tab > Sales Order = Edit.

7.    Go to Permissions tab > Lists sub tab > Customers = Edit.

8.    Then, log out and log back in using other role. In the example, Customer Service Manager Role.

9.    Go to Customers > Sales Order > New > you will see now the 'plus' button in the Shipping tab.