Getting an odd result: mysqli_fetch_array() expects parameter 1 to be mysqli_result

Getting an odd result: mysqli_fetch_array() expects parameter 1 to be
mysqli_result

I keep getting weird results from this query.
Not that I am not using PDA because this is just a prototype. In
production I plan on tightening all of the screws and making it more
secure.
include ('../includes/DBConnect.php'); //exactly how it is in other
working files
$query = "SELECT * FROM CHARACTERS WHERE USER_ID=(SELECT ID FROM USERS
WHERE EMAIL='"+$_SESSION['user']+"') ORDER BY id DESC"; //I have copy
pasted this into mysql and it worked, switching the session variable with
a string
I get an error with the this line
while($row = mysqli_fetch_array($character_list)){
Warning: mysqli_fetch_array() expects parameter 1 to be mysqli_result,
boolean given in C:\xampp\htdocs\Node2\public\main.php on line 36
I know this has to be stupid. I can't figure it out. I just looked at
documentation and other files I have written that worked. And a few stack
overflow threads to no avail.
Thank you so much.