R12.2.3 Procurement: No backend server available for connection error message due to performance issue

If you are on EBS R12.2.3 or planning on going to it, make sure you add into your testing suite the issue detailed in article "Performance When Searching Items To Receive In iProcurement: No Backend Server Available For Connection" which note ID 2054046.1 tells us is due to an incorrect index and what patches are available to resolve the issue.