Run this after running the first 8 steps you posted earlier and show us the results. There are no conversions from character to data/time occurring so there should be no conversion errors:

SELECT

LTRIM(SUBSTRING (Col1, 1, 20)) AS 'DateTimeStamp',

LTRIM(SUBSTRING(Col1, 71, 6)) AS 'LSN',

LTRIM(SUBSTRING (Col1, 21, 18)) AS 'FileSize',

LTRIM(SUBSTRING (Col1, 40, 1000)) AS 'FileName1'

FROM

#OriginalFileList

ORDER BY

LSN