How to check if there is empty cell in a range by using IF Statement ?

I used to use IF Statement to detect empty cell within a range as EXAMPLE
listed below. It works in the past but suddenly fails and output "#VALUE".
Why ?

BEFORE :
Statement : =IF(A2:A4="",1,0)
When A3 = "Null"
Output : "1"

PRESENT :
Output : "#VALUE"