I know this is a really old post - but like to contribute back. But I had the same issue. I was able to solve it for my part.
Putting in debug mode I was able to get an important message:
_discover_file: /Users/wtaylor/Downloads/logstash-2.2.2/bin/Wayne.csv: skipping because it was last modified more than 86400.0 seconds ago {:level=>:debug, :file=>"filewatch/watch.rb", :line=>"310", :method=>"_discover_file"}
Pushing flush o
When I touched the log file I was reading in boom data started to process