The latest Mac OS is 10.15.1 (Catalina), released Tuesday, October 29th, 2019. If you have upgraded to 10.15 already, get this 10.15.1 update. (Remember that 10.15 is a significant upgrade and you should be sure that your apps are ready for it. I recommend waiting for 10.15.2 before upgrading.) See this article for information about compatibility with 10.15.