In SSIS package, if you create a fixed width flat file, SSIS does NOT add new line character (CRLF) at the end of the row.
So when you run the package, all the data are stored in one single line in the flat file.
Add CRLF Column to Destination
You need to add additional column to the fixed width flat file and name it as CRLF (or name of your choice).
This column must have width of 2 characters.
Here are two ways to add new line character after each row
Option 1. New Line Character in Resultset in Source
Add new line character as a column in the SELECT statement. This example assumes source as SQL Server.
SELECT CHAR(13) + CHAR(10) AS CRLF
Options 2. New Line Character as Derived Column
Create a derived column called CRLF using the following expression.
Now you have CRLF column in source and destination. Once you map source column to destination column, it will work.