Another hazel worker process is processing folder ???

I may be missing something here because I am new to Hazel but I am trying to get a rule to process by selecting the "Run Rules Now" menu option and nothing happens. When I look in the log file (with DEBUG mode turned on) I see the following statement:
2014-03-28 08:24:13.548 hazelworker[20289] Another hazelworker process is processing folder (null). Exiting.

Anyone have any ideas - I did a cursory search of the forum for this error and the search came up empty.

It means Hazel is already working on that folder. Beyond that, are you seeing any sort of problem?

Basically the rules I have put in place are not being processed. Being new to Hazel I am trying out a variety of rules to try to understand how best to use the tool. My lack of familiarity could of course be the source of the problem (dare I say it is likely).

I have been keeping an eye on the log files and didn't understand why when I manually run the rules I do not see anything happen and I saw this message. Since this never seemed to change and nothing seemed to happen I decided to create this post.

I'll dig in some more and see if I can figure this out.

Thanks very much for the help!

Launch Activity Monitor and see if there are any hazelworker processes running. Check periodically as usually they should not run for that long (more than a few minutes). If you find one in particular running for a long time (use the PID to identify them), select it and do "Sample Process" on it and email that in to support.