Works for me:
CREATE TABLE #temp (col1 datetime2 default current_timestamp NULL)
INSERT INTO #temp(col1) SELECT '2011-12-14 12:09:21.472'
SELECT * FROM #temp
GO
DROP TABLE #temp
Can you supply a...

I think this might answer your question:
DECLARE @percentComplete float = 0.55
select CONVERT(decimal(38,38),@percentComplete )

SELECT * FROM CTE OPTION(RECOMPILE)
You have too many brackets and you don't need to put it in a common table expression.