Yes, it is possible to use the #N/A error as criteria when using SUMIF. The formula you provided, =SUMIF(B3:B32,ISNA(C3:C32)), is on the right track but needs a slight adjustment.

Here's the correct formula: =SUMIF(C3:C32,"#N/A",B3:B32)

This formula will sum the values in B3:B32 only if the corresponding cell in C3:C32 contains the #N/A error.

Here's how it works:

1. The first argument, C3:C32, is the range of cells that will be checked for the #N/A error.
2. The second argument, "#N/A", is the criteria that the formula will look for in the range specified in the first argument.
3. The third argument, B3:B32, is the range of cells that will be summed if the criteria in the second argument is met.

Make sure that the cells in the range C3:C32 actually contain the #N/A error and not just the text "#N/A". You can check this by selecting one of the cells and looking at the formula bar. If it shows #N/A, then the cell contains the error. If it shows "#N/A", then it's just text.