While submitting request to download Form 16 / 16A, deductor has entered details correctly in Part 1 and Part 2 in validation details screen, yet it shows error as 'Invalid Details' in Part 1 and Part 2. What should deductor do?

Details to be filled in validation screen should be exactly the same as reported in the TDS statement. If you have filed any correction statement, Token Number and other details should be as per the latest correction statement..