Based on your data, rather than double evaluating etc why not just use:

C2: =SUMIF(E:E,A2,F:F)
copied down
and apply a Custom Format to C2:C98 of: [=0]"";General ... thereby making 0's appear as blanks.

NOTE: I only just noticed your title - I have edited on this occasion given I'd already made the mistake of replying - ensure your titles are appropriate going forward.