3826567 - Error: “We are sorry that your request cannot be completed. The reservation system has advised the fare you selected is no longer valid. This may happen when the last seat is sold on a flight, or when a fare is removed from the system ..."

The following error message was displayed when clicking on Reserve Flight and Continue button on Review and Reserve Flight page in Concur Travel. 

"We're sorry..."
"We encountered an issue that prevented us from completing your request"
“We are sorry that our request cannot be completed. The reservation system has advised the fare you selected is no longer valid. This may happen when the last seat is sold on a flight, or when a fare is removed from the system. Please try again with a different itinerary or contact your fulfillment travel agency for assistance.” 

KBA , CON-SRV-TRV-ADM-LAN , View Airlines , Problem