Cannot complete this action as the Secure Store Shared Service is not responding. Please contact your administrator.

Using SharePoint 2013;

Issue: We are getting the following error when the portal page is accessed.

"Cannot complete this action as the Secure Store Shared Service is not responding. Please contact your administrator."

Cause: Secure store service is not running or not set with proper permission.

Resolution: In IIS, change the secure store service Application pool identity to a dedicated user if it is pointed to Network service/Local Service.

Because Secure Store is used to store sensitive information, for better security run the Secure Store Service in a separate application pool that is not used for any other service.

Reference: https://technet.microsoft.com/en-us/library/ee806889.aspx