1953417 - Error:An Approver Could not be Determined. Either Approval is Not Relevant or the Task is Unassigned. Please contact your system administrator.

The approvals process for Supplier invoices is defined as:

Step1:
Work distribution: Supplier Invoice Approver
Conditions: Random Exception Check Percentage is Less than or equal to "100"

But, the Exception prone supplier invoice never undergoes for approval. Instead the approval tab of supplier invoice displays an error message:An approver could not be determined. Either approval is not relevant or the task is unassigned. Please contact your system administrator.

This is also applicable for the invoices without any exception, but with the message : "An approver could not be determined. Either approval is not relevant or the task is unassigned. Please contact your system administrator." in the Approval tab. 

No approver determined, approval task not available , KBA , an approver could not be determined , AP-SIP , Supplier Invoice Processing , How To