Need some help for SSRS.
The column % expression is
=iif(sum(Fields!ColumnA.Value) = 0 or sum(Fields!ColumnB.Value) = 0,0,sum(Fields!ColumnB.Value) / sum(Fields!ColumnA.Value))

But I am getting #Error if ColumnA is zerro and no error if ColumnA and B had no value. Please advise what is wrong with the expression.

Thank for the hint RogiePronk. The following works.
=iif(sum(Fields!ColumnA.Value) = 0 or sum(Fields!ColumnB.Value) = 0,"", sum(Fields!ColumnB.Value) / iif(sum(Fields!ColumnA.Value)=0,1,sum(Fields!CalumnA.Value)))