I do not believe there is a default connection for SAP ECC. You get clipboard importing when you attempt to copy and paste data into tableau. Can you be a bit more descriptive of the steps you've taken to do this? There are a few other options of getting tableau to connect to SAP ECC. They will involve getting a database between the two.
I followed the below steps.
1.Tableau desktop clicked the SAP NETWEAVER Business Warehouse
2. Selected the connection
3. Typed the User name and pwd
I got the page as Cube data as mentioned below
I want the tables inside the Cube data
This is something you have to work on with your SAP administrator. Cube is either misconfigured or you don't have permissions.