I think a warning is misleading in this case. What is happening here is that the list of all processes in the system is found, and then later the procfsDir/<pid>/stat file for each is opened. This warning is thrown when the process finishes before the stat file is opened, and hence the file is no longer there. This could normally happen, and shouldn't signify a waring. An info message is sufficient. I'll be uploading a patch momentarily.