Report Builder returning "Expression expected" on a textbox

Question

I'm confused, how is this not an expression? I get the error in the title using the expression below as a placeholder for a textbox.

=IF(COUNT(Fields!item.Value, "FGInputTest")=0,"Item and lot combination do not exist", First(Fields!item.Value, "FGInputTest"))

Answer 1

The SSRS if statement is spelt 'Iif' not 'If'