Uistring error setProperty

I have students working on their Unit 5 Hackathon Project and we are constantly running into this error and nothing will work - WARNING: Line: 61: setProperty() value parameter value (1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20,21,22,23,24,25,26,27,28,29,30,31,32,33,34,35,36,37,38,39,40,41,42,43,44,45,46,47,48,49,50) is not a uistring. WARNING: Line: 62: setProperty() value parameter value (undefined) is not a uistring. WARNING: Line: 63: setProperty() value parameter value (undefined) is not a uistring.*

They have modeled it like previous projects and can’t get it to work
Here is their project to look at.

Remove the square brackets in your list declaration statements at the top. For example,
var usaRank = (getColumn("Top 50 USA", "Position"));
instead of
var usaRank = [(getColumn("Top 50 USA", "Position"))];