VAR problem

Hi Rupilas, 

It looks like you're commenting everything out. When you use an comment operator everything after the operator becomes a comment. Try using /*  to open and  */ to close the comment instead.

Sales Summary =
VAR SalesTableWithCustKey = Filter(/* Filter Table */ 'Fact Sale', /* Filter Condition */ 'Fact Sale'[Customer Key]>0)
VAR SalesTableGrouped = SUMMARIZE(/* Table to Summarize  */ 'SalesTableWithCustKey','Fact Sale'[Customer Key],/* Aggregated Colum Name  Expression */ "Total Spend", SUM('Fact Sale'[Total Including Tax])
VAR SummaryTableFiltered = TOPN(/* Numbers of rows to return */ 10, /* Table to filter */ SalesTableGrouped, /* Order by Expression */ [Total Spend])
 RETURN SummaryTableFiltered