Was thinking of having a separate category for QlikView error message for quite some time, fortunately it’s happening with this post.
“Error: Error in expression: PEEK is not a valid function”
Cause:
Used Set statement for storing the result of peek expression in Script.
Set vVar = peek();
Solution:
Replace Set with Let.
Otherwise go as below,
Let vTemp=peek(..);
Set vVar=$(vTemp);
And also consider what if peek expression returns null value. That variable itself will not be available.
But still $(vVar) will return null and $(#=vVar) will return zero.
QlikTab 