As of this time, Hazel is not compatible with Catalina. Catalina introduces a number of changes and bugs which affect Hazel, many of which are still unresolved. It is strongly advised that you do not upgrade to Catalina if Hazel is an important part of your workflow.
Apple: We would like to contact you concerning a crash. Could you please file an FBA?
Me: You’re contacting me now, but sure. files FBA #1
Apple: marks FBA #1 as unactionable
Me: files FBA #2
Apple: crickets
Me: files DTS to look at FBA #2
Apple: crickets*