I am using this formula.

=SUMPRODUCT(--($C$3:$C$180=I3);--($F$3:$F$1800))/COUNTIF($C$3:$C$180;I3)

Sometimes the ranges have value like:

#N/A

#VALUE!
#NUM!

Is there a way to have make the formula "ignore" the cells w/ errors ?

Thank you in advance.