3803700 - Error: You're not authorized to use this app. Please contact the administrator. When accessing Approval Task in My Inbox app.

When accessing an Approval Task from the My Inbox app in SAP Ariba Invoicing, the following error is displayed:

You're not authorized to use this app. Please contact the administrator.

The user is unable to access or process the approval task from the My Inbox application.

SAP Ariba Invoicing, CIM, My Inbox, Approval Task, Authorization Error,  Identity Authentication Service, CIM_Auditor, CIM_Managed_User , KBA , S2P-CIM-WFL , Workflow, My Inbox, RFI etc. , Problem