The next macOS release, macOS Catalina (10.15), is slated for release in the Northern hemisphere fall (Late September, 2019).
Apple have recently made the macOS Catalina beta release available to users as part of their beta software program.
Older versions of Geneious, and the current supported versions of Geneious (Geneious R11.1 and Geneious Prime 2019.2) have not yet been tested on macOS Catalina beta, and may not function correctly.
Apple notes that macOS Catalina is beta software, and as such, "has not yet been commercially released by Apple, it may contain errors or inaccuracies and may not function as well as commercially released software."
We strongly recommend that Geneious users DO NOT upgrade to macOS Catalina beta.
We will endeavour to address any compatibility issues on macOS Catalina before its official release to ensure ongoing compatibility.