When prompted - do you want to reverse this invoice I received the following error: DETAILS REQUIRED TO REVERSE THIS INVOICE CANNOT BE FOUND. How can they be found so that I can reverse it?

are you using AP-C?
 
if it is an invoice against a purchase order and the purchase order is closed, you may receive such a message.
 
go to View PO Receivers, PO-D, locate the purchase order number and select ReOpen Purchase order, then try reversing its invoice and see if it will process.
 
hope this helps.