If you’ve set up your Secure Store, and designed your External Content Type, and set up the list from there, and you get this message (in the subject line), chances are that you are forgetting one last thing.

Of course, in the Secure Store Service you set up, you assigned permissions. But that’s not the last place you need to do this. When you get this error, go back to ‘Application Management’ and choose/click on ‘Manage Service Applications’, under ‘Service Applications’. Once you get there, instead of ‘Secure Store Service’, click on the ‘Business Data Connectivity Service’ link. Check/Select the checkbox beside the List you created, and in the ribbon, click the ‘Set Object Permissions’ button.

Here, you’ll need to Add and assign the general users who are authorized for viewing the list, and give them ‘Execute’ permissions. Lastly, you need to add some user in an administrative role with more robust permissions. As for me, I usually assign all the permissions available (check all the permission checkboxes).

Once this is done, click the ‘OK’ button and you should be good to go. This should get rid of the error in the subject line of this post, and your data should be viewable.