IF(ISNA(INDEX,Match)"Yes", "No"

Hi
Have you committed it with Ctrfl+Shift+Enter ? It is an array formula.

Your formula is an "array formula" and needs to be entered with CTRL+SHIFT+ENTER so that curly braces like { and } appear around the formula. If you do that correctly then it should display the correct answer.

Assuming that N/A comes about because there are no rows that match the criteria you could use a simple non-array version with SUMPRODUCT, i.e.

=IF(SUMPRODUCT(('TB vs. ANET Consol.'!$D$2:$D$166=C5)*('TB vs. ANET Consol.'!$E$2:$E$166=D5)),"No","Yes")

if you are just testing the match them all you need is
=IF(ISNA(MATCH(1,('TB vs. ANET Consol.'!$D$2:$D$166=C5)*('TB vs. ANET Consol.'!$E$2:$E$166=D5),0)),"yes","no")
array entered

Attach a sample workbook. Make sure there is just enough data to make it clear what is needed. Include a BEFORE sheet and an AFTER sheet in the workbook if needed to show the process you're trying to complete or automate. Make sure your desired results are demonstrated, mock them up manually if needed. Remember to desensitize the data.

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