The problem is a subquery is being used but not aliased. It is when the variable @query is being defined

To fix it change to:

set @query = '

DECLARE @cols NVARCHAR(max)

SELECT @cols = STUFF(

( SELECT DISTINCT ' + case when @colTop is not null then 'Top ' + @colTop else '' end + '''],['' + t2.' + @pivotField + '

FROM

(SELECT CONVERT(nvarchar(max),a.' + @colField + ') AS ' + @pivotField + '

FROM

(SELECT DISTINCT ' + @colField + '

FROM ' + @colTable + ' x

' + case when @colWhere is not null then 'WHERE ' + @colWhere else '' end + '

) AS a

) AS t2

ORDER BY ''],['' + t2.' + @pivotField + ' FOR XML PATH('''')

), 1, 2, '''') + '']''

select @cols

'

All I have added is ' x '

Hope this helps

Phil