Excel SUMIFS throws #Error for two criterias and =MONTH function

I have the following case in Excel where I have hours based on date and task.

Based on an =UNIQUE() I add all my tasks in I column and in J column I am trying to add the hours based the task and the current month defined on I2.

That formula will throw me the #Error but I can’t really understand why.

Thank you for your time!

>Solution :

You may try this in Sheets

=sumifs(D:D,C:C,I4,index(month(A:A)),I$2)

• the parameter month(A3:A) is not applied across the whole A3:A column_range & is same as writing it as month(A3). You may need to wrap it in an arrayformula / index so that it is applied to the whole column_range. Otherwise you will be prompted with Array arguments to SUMIFS are of different size. error