I am getting the above error on the challenge.  Here's what my query looks like.

q = load "0Fb46000000CamaCAC/0Fc46000000CeOsCAK";
q = filter q by 'Closed' == "false";
q = group q by ('Close_Date_Year', 'Close_Date_Month', 'Forecast_Category');
q = foreach q generate 'Close_Date_Year' + "~~~" + 'Close_Date_Month' as 'Close_Date_Year~~~Close_Date_Month', 'Forecast_Category' as 'Forecast_Category', sum('Column1') as 'sum_Column1';
q = order q by ('Close_Date_Year~~~Close_Date_Month' asc, 'Forecast_Category' asc);
q = limit q 2000;

Here's how it is saved.

What's the issue?