If you create a File delimited connection to a CSV file and define the schema, you can see the contents of the file by right-clicking on the connection element in the Metadata section, and selecting Data Viewer. You can also see the schema, so the file is reading correctly.
The issue is that when switching to the Profiling view, if you select Column analysis and select the added connection, it shows up in the Data Preview configuration, but if you click Refresh Data, nothing shows. TDQ-14743 was filed for this issue.
Create the file connection in Delimited mode (this is the default mode).
This issue has been resolved in 6.4.2, 6.5.1, and 7.0.1.