Set up a basic Nested IF that does nothing more than display the mailer round status based upon a set of dates entered. With no dates inputted the formula displays the correct value, however once I input a date it returns "INVALID OPERATION". I've attached a copy of the formula below for commentary. Appreciate the help.
=IF([1st Round]36 = 0, "Ready for Vet", IF([2nd Round]36 = 0, "Round 1 Sent", IF([3rd Round]36 = 0, "Round 2 Sent", IF([4th Round]36 = 0, "Round 3 Sent", IF([5th Round]36 = 0, "Round 4 Sent", "Round 5 Sent")))))