NULL value comparison in IF statement
If you have field in DE that its value is not always populated for a particular row (customer) and you test field value against any value cloud page will throw an 500 – internal server error.
%%[ var @field;// null value if @field == 4 then //500 endif ]%%
To fix this, you will simply need to add another AND-condition to test field value for NULL with NOT IsNull()
%%[ var @field;// null value if NOT IsNull(@field) AND @field == 4 then //do something endif ]%%
