I have been trying to count the number of occurrences when the value in the
first column is 1277 and the value in the second column is "Yes". I have
come up with the following formula:

=SUMPRODUCT(('Master Report'!$H$2:$H$2000=B1)*('Master
Report'!$K$1:$K$2000="Yes"))

The result is #N/A

Please can anyone help!