I'm not sure how to describe this as anything other than a bug. It is intermittent, but does show up after working with the Hazel window (in SysPrefs) open for a while. A while is >10 min or so.
I have created a rule as a template for one of the processing folders. I clone it to use some of the file matching items without re-entering them each time.
As I work with the files, leaving Hazel open, viewing the contents of a file, pulling criteria, adding it to new rules in Hazel and testing it, most works fine when working with rules. However, after about 10min or so, I cannot double click to open the template rule to edit/view it. A double-click does nothing. Double-clicking on other, active rules, seems to work most of the time. There are times when other, active rules are non-editable also, but those times are more rare.
Either way, closing System Preference and re-opening usually solves the issue.
If there is any debug or other info I could send to help find the issue, pls let me know.
Mike