Unpivot only selected columns not working

Hi Guys,

I'm editing a query (table) which I've loded in from SQL and it allows me to Unpivot only selected columns and I'll rename the two columns as date and values.  But when i press close and apply, it doesn't apply the changes and says "The column 'first column' of the table wasn't found".

I have no problem in doing the same thing with data loaded in from excel.

Thanks guys.