Counting Two Sets of Criteria Between Multiple Spreadsheets

Hi,

I have data in 15 different worksheets in one workbook. I am trying to count data when it matches two separate sets of criteria (status & grade). Status is in the H column in the individual spreadsheets and Grade is in the B column in the individual spreadsheets. I have created a calculations page where l listed the separate spreadsheet names (column A), grade options (COLUMN C), and status options (COLUMN B).

I have entered the below formula but get the #REF error message. I cannot figure out what the issue is. Please help! Thank you in advance.

=SUMPRODUCT(COUNTIFS(INDIRECT("'"&$A$4:$A$18&"'!"&"H3:H100"),$B$4,INDIRECT("'"&$A$4:$A$18&"'!"&"B3:B100"),C4))