DK, a couple things you might want to check:
1) First, check to ensure that triggers are enabled in your AR client policy. They are disabled in the default policy, and must be enabled before triggers will work.
2) Check your file exceptions in your AR client policy. TXT files are excluded from AR by default. As a test, you might consider testing with files that have a different extension. You can choose to remove .txt from excluded extensions if you like.