Summing multiple columns?

Can you sum multiple columns based on two conditions?

I have a selection of data that ranges from column D:DE
In column B is condition 1 in Column C is condition 2

I have tried

Formula:

=sum(if('Data'!$B:$B=B10,if('Data'!$C:$C=C9,'Data'!$D:$DE,0),0))

and

Formula:

=Sum(('Data'!$B:$B=B10)*('Data'!$C:$C=C9)*('Data'!$D:$DE))

But i am getting either £0.00 or #Value or #N/A

Whats wrong here?

Dan