WS_FTP Server - "forced close listener socket" log entry

Question/Problem: What does the forced close listener socket entry mean in my WS_FTP Server logs?  Is there a problem with my server?

Answer/Solution: This log entry indicates that the network connection to the FTP 'command channel' was closed by WS_FTP Server.  It does not necessarily indicate an error and may appear often in the logs.  Normally, an FTP client issues a QUIT command before the network connection to the command channel is closed, but this does not always happen.