I'm new to einstein analytics and I keep getting the following message in the step 1. I would appreciate if someone could let me know what does the error means and how I need to fix it.



and my SAQL Query is below, I'm not sure what is wrong as I'm still trying to learn EA.

q = load "Beattie_Subs";

cancel = group q by ('Churn_Date_Year', 'Churn_Date_Quarter');
cancel = foreach cancel generate cancel.'Churn_Date_Year' + "~~~" + cancel.'Churn_Date_Quarter' as 'ActivityDate_Year~~~ActivityDate_Quarter', count() as 'New Quarter Cancellations';

cancel = group cancel by ('ActivityDate_Year~~~ActivityDate_Quarter');
cancel = foreach cancel generate cancel.'ActivityDate_Year~~~ActivityDate_Quarter' as 'ActivityDate_Year~~~ActivityDate_Quarter', coalesce(sum(cancel.'New Quarter Cancellations'),0) as 'New Quarter Cancellations', coalesce(sum(sum('New Quarter Cancellations')) over ([-1..-1] partition by all order by ('ActivityDate_Year~~~ActivityDate_Quarter')),0) as 'Previous Quarter Cancellations';

sub = group q by ('Subscription_Date_Year', 'Subscription_Date_Quarter');
sub = foreach sub generate sub.'Subscription_Date_Year' + "~~~" + sub.'Subscription_Date_Quarter' as 'ActivityDate_Year~~~ActivityDate_Quarter', count() as 'New Quarter Subcribers';

sub = group sub by ('ActivityDate_Year~~~ActivityDate_Quarter');
sub = foreach sub generate sub.'ActivityDate_Year~~~ActivityDate_Quarter' as 'ActivityDate_Year~~~ActivityDate_Quarter', coalesce(sum(sub.'New Quarter Subcribers'),0) as 'New Quarter Subcribers', coalesce(sum(sum('New Quarter Subcribers')) over ([-1..0] partition by all order by ('ActivityDate_Year~~~ActivityDate_Quarter')),0) as 'Previous Quarter Subcribers';

result = cogroup sub by 'ActivityDate_Year~~~ActivityDate_Quarter' full, cancel by 'ActivityDate_Year~~~ActivityDate_Quarter';
result = foreach result generate coalesce(sub.'ActivityDate_Year~~~ActivityDate_Quarter', cancel.'ActivityDate_Year~~~ActivityDate_Quarter') as 'ActivityDate_Year~~~ActivityDate_Quarter', sum(cancel.'New Quarter Cancellations')/(sum(sub.'New Quarter Subcribers') + sum(sub.'Previous Quarter Subcribers') - sum(cancel.'Previous Quarter Cancellations')) as 'Churn Rate';