Fix "Unable to render the data. If the problem persists, contact your web server administrator." Issue in SharePoint BCS

Problem:
Tried created an external list SharePoint 2016 using business data connectivity services, configured secure store target application and created external list in SharePoint. All went good, however the external list displayed this error message with a correlation ID.
Unable to render the data. If the problem persists, contact your web server administrator.
Ran ULS Log viewer and found this message in the logs:
Error while executing web part: Microsoft.BusinessData.Infrastructure.BdcException: The shim execution failed unexpectedly - Unable to obtain the application proxy for the context.. ---> Microsoft.Office.SecureStoreService.Server.SecureStoreServiceException: Unable to obtain the application proxy for the context.   

Solution:
The root cause of the problem is: The web application is not associated with the secure store service application. So, the solution is:

• Go to SharePoint 2013/2016 Central Administration site
• Application management >> Click on Configure service application associations under Service Applications.
• Pick the web application in which your site exist, Check the "Application proxy group" column >> Make sure the BDC and secure store service applications check boxes checked.