I am getting below expression error when trying to access Task report by the ba

If the Admin user expression returns an array that does have data then that's why this would work. Remember, the error shows that for the basic user the expression is returning an empty array somewhere and you're trying to get item 1 out of that empty array.

If the Admin user expression returns an array that does have data then that's why this would work. Remember, the error shows that for the basic user the expression is returning an empty array somewhere and you're trying to get item 1 out of that empty array.