I would guess that you have created a column in your dataflow called 'Copy of SSN' and that the error is occurring because you have mapped this column to one in your destination which cannot accommodate it (possibly because the width is too small).
Solution is to change the data type of the target column accordingly.
If you haven't even tried to resolve your issue, please don't expect the hard-working volunteers here to waste their time providing links to answers which you could easily have found yourself.