Declare a Read-Only Variable with the const Keyword: Unexplained Error

Tell us what’s happening:

Your code so far

function printManyTimes(str) {
   'use strict';
   // change code below this line
   const SENTENCE = str + ' is cool!';
   for(let i = 0; i < str.length; i+=2) {
   // change code above this line

Your browser information:

User Agent is: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_13_5) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/67.0.3396.87 Safari/537.36.

Link to the challenge:

I get this error:

// running test
Unexpected token ?
// tests completed

I believe it should pass!?!

See this