Access denied by Business Data Connectivity.

Access denied by business data connectivity when creating external content type

Solution :

Go to Central Administration -> Manage Service Applications -> Business Connectivity Service application

Select the External Content type which you have created, and click on Set Object Permissions button in the ribbon,

In my case its NewExternal content type.

Type EveryOne and click on Add button and Select Execute Check box and Click on OK Button

That's set..., you will be able to see the result , if still getting same error select Edit checkbox and try it.