I have an app where I am using rebex file transfer pack version 4.0.6930. After upgrading to any version after 4.0.6930 the app is creating too many threads.
I am concurrently connecting to multiple ftp servers. In new version the app creates threads more than the open connections but earlier we were able to manage those connection with lesser number of threads.
E.g if we open 100 connections we were able to manage those using ~45 threads. Now it creates 100+ threads.
You can download the sample code from https://drive.google.com/open?id=1MDCVAm0BNtXPGASlIHYOVgZXyMf2L5UQ
I am using version 4.0.6930 in this app. Try updating to latest version and see the difference in number of threads in task manager.